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142 | Texture/Material/Finish | Feature Request | 3.70 beta 37a | Very Low | Low | camera_view pigment from MegaPOV | Tracked on GitHub | |
Future release |
Task Description
I probably don’t have to explain why the camera_view pigment in MegaPOV was important, but I will list some reasons anyway:
1) post-processing could be performed in-scene 2) new types of focal blur effects could be created 3) feedback fractals were possible
I’m sure there are many others, as this is one of those features that has undetermined potential!
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151 | Runtime error | Possible Bug | 3.70 beta 37a | Very Low | Low | No way to cancel save while parsing, never ending error... | Tracked on GitHub | |
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Task Description
On Windows, when I try and save a file while it is being parsed prior to rendering, I get an error, “Failed to save file: The operation completed successfully”, with a single OK button to click. Despite the weird wording, I’m OK with that.
However after clicking OK I get the error, “Failed to save file ‘...’“, with three buttons: Cancel, Try Again, Continue. Not sure what “Continue” means in this context, given that the possibilities would seem to be covered by the other two buttons. Whatever.
Also, sometimes I get a message with only a single “Retry” button. Not sure what the exact message was.
Anyway, the real problem is that, regardless of which button I press, the program continues to spawning the same error message endlessly. Luckily there is a delay between them, but still it would be nice to have at least one of the three buttons *stop* POV-Ray from asking me again.
Also, once the program finishes parsing the file and it becomes possible once again to save the file, it does nothing. I.e. it doesn’t save the file. So what’s the point of the message and all the options? Why not just say, “Unable to save the file, file is parsing” and be done with it?
I think I recall the same behavior in 3.6.2, so it’s nothing new that’s been introduced.
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140 | Platform-specific | Feature Request | 3.70 beta 37a | Very Low | Low | "Reload" option in File menu | Tracked on GitHub | |
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Task Description
Would be great to have a “Reload” option in the File menu to manually reload the current file from disk, discarding all subsequent changes since the last save.
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127 | Parser/SDL | Feature Request | 3.70 beta 37a | Very Low | Low | Expandable arrays | Tracked on GitHub | |
Future release |
Task Description
Currently, arrays are of a fixed size. You can’t add or remove items to/from an array. I think it would like arrays to be expandable with no fixed and pre-determined size.
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129 | Parser/SDL | Feature Request | 3.70 beta 37a | Defer | Very Low | Hash arrays | Tracked on GitHub | |
Future release |
Task Description
Currently, array items may only be referenced by their index number (an integer). It would be nice to also be able to assign string values as array indexes, as in other scripting languages.
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145 | Parser/SDL | Feature Request | 3.70 beta 37a | Very Low | Low | Stack trace report on error | Tracked on GitHub | |
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Task Description
In other languages if you encounter an error you’ll often be presented with a stack trace showing not only the file and line number the error occurred at, but also any calling functions and _their_ calling functions and so on.
Currently, Povray reports the line number of the error as well as the last five or so lines prior to the error. This is usually OK in simple scenes, but breaks down when you start making use of inclusion and macros.
Let’s say you have a macro located in a file that you then include in your scene. Within your scene you call the macro multiple times, passing input to it. However, by accident you pass _invalid_ input to the macro at some point, resulting in an error when parsing. In this case Povray will report the error as belonging to the macro whereas the actual bug exists in the calling code. If the macro is called more than once in your scene it can be difficult to figure out _which_ instance is the one supplying the bad input.
Not sure how much of this is achievable in Povray.
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131 | Other | Feature Request | 3.70 beta 37a | Very Low | Low | Ability to change the order of editor tabs by dragging ... | Tracked on GitHub | |
Future release |
Task Description
See Notepad++ or EditPad Lite for examples.
It would be nice to be able to drag tabs in the editor window to change their order, so as to group opened files together by relevance for instance.
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118 | Light source | Feature Request | 3.70 beta 37a | Very Low | Low | More efficient handling of fading lights | Tracked on GitHub | |
3.71 release |
Task Description
Currently, fading light sources are used for lighting and shadow calculations even when so far away as to no longer have any effect on the outcome. The proposed solution is to add a new keyword fade_cutoff_distance which tells povray to ignore the light source when alluminating a point at larger distance.
A sample implementation is provided in the attached files. These changes are still based on beta 34 as sources for the current beta are not yet available, and starting to merge changes to beta 35 only at this time didn’t seem worth the effort. Also, please disregard, changes in the CVS header comments (I also use CVS locally for managing source files).
Further considerations regarding this feature:
- For special effects this feature can also be used if the light source does not actually use fading. On the other hand, cutting the light at some distances can be considered an extreme form of fading which may justify the keyword name anyhow.
- Depending on how FS#46 is implemented, the test for cutoff may then be needed at another location as well.
- The default value currently is 0 (or *no* cutoff distance). For #version 3.7 of higher, the default could be chosen automatically based on the light source intensity and adc_bailout, although it may then need to be overriden by the user for extreme pigments.
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133 | Geometric Primitives | Feature Request | 3.70 beta 37a | Defer | Very Low | Subdivision support | Tracked on GitHub | |
Future release |
Task Description
Someone built a version of Povray with internal support for automatic subdivision of meshes. See:
http://www.cise.ufl.edu/~xwu/Pov-Sub/
Would like to see this feature added natively to Povray.
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178 | Texture/Material/Finish | Feature Request | 3.70 beta 39 | Very Low | Low | Modify metallic reflection code to better work with con... | Tracked on GitHub | |
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Task Description
The combination of metallic reflection with conserve_energy causes the reflection to lose colour, as demonstrated by the following scene:
global_settings {
max_trace_level 10
}
camera {
right x*image_width/image_height
location <-2,2.6,-10>
look_at <0,0.75,0>
}
light_source {
<500,300,150>
color rgb 1.3
}
sky_sphere {
pigment {
gradient y
color_map {
[0.0 rgb <0.6,0.7,1.0>]
[0.7 rgb <0.0,0.1,0.8>]
}
}
}
plane {
y, 0
texture { pigment { color rgb 0.7 } }
}
#declare M=
material {
texture {
pigment {rgbt <1.0,0.7,0.2,0.99>}
finish {
ambient 0.0
diffuse 0.5
specular 0.6
roughness 0.005
reflection { 0.8, 1.0 metallic }
conserve_energy
}
}
interior { ior 1.5 }
}
box {
<-0.2,0,-2.3>, <0.0,4,0.3>
material { M }
rotate z*5
rotate x*2
}
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177 | Light source | Feature Request | 3.70 beta 39 | Very Low | Low | Add support for conserve_energy to shadow computations | Tracked on GitHub | |
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Task Description
The following scene gives a comparison of current conserve_energy handling in standard shadow computations vs. photons.
Note how the rather highly reflective slabs fail to cast shadows, except where the photons target sphere enforces computation of shadow brightness to be done by the photons algorithm.
For more realistic shadowing without the need to enable photons, I suggest do add proper conserve_energy handling to the shadow computation code (which shouldn’t be too much effort).
global_settings {
max_trace_level 10
photons { spacing 0.003 media 10 }
}
camera {
right x*image_width/image_height
location <-2,2.6,-10>
look_at <0,0.75,0>
}
light_source {
<500,300,150>
color rgb 1.3
photons {
refraction on
reflection on
}
}
sky_sphere {
pigment {
gradient y
color_map {
[0.0 rgb <0.6,0.7,1.0>]
[0.7 rgb <0.0,0.1,0.8>]
}
}
}
plane {
y, 0
texture { pigment { color rgb 0.7 } }
}
#declare M_Glass=
material {
texture {
pigment {rgbt 1}
finish {
ambient 0.0
diffuse 0
specular 0.2 // just to give a hint where the sphere is
}
}
interior { ior 1.0 }
}
#declare M_PseudoGlass=
material {
texture {
pigment {rgbt 1}
finish {
ambient 0.0
diffuse 0.5
specular 0.6
roughness 0.005
reflection { 0.3, 1.0 fresnel on }
conserve_energy
}
}
interior { ior 1.5 }
}
sphere {
<1.1,1,-1.3>, 1
material { M_Glass }
photons {
target 1.0
refraction on
reflection on
}
}
// behind target object
box {
<-0.2,0,-2.3>, <0.0,4,0.3>
material { M_PseudoGlass }
rotate z*1 // just to better see the reflection of the horizon
}
// before target object
box {
<2.4,0,-2.3>, <2.6,4,-0.3>
material { M_PseudoGlass }
photons { pass_through }
rotate z*1 // just to better see the reflection of the horizon
}
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172 | Image format | Unimp. Feature/TODO | 3.70 beta 39 | Very Low | Low | Re-implement progressive image output | Tracked on GitHub | |
Future release |
Task Description
With previous versions of POV-Ray, it was possible to turn off display output, but still assess the output during render by viewing the output file as it was progressively generated. This allowed e.g. to run a long render on a remote machine as a background process, and check the output from time to time via FTP or similar.
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183 | Texture/Material/Finish | Possible Bug | 3.70 beta 40 | Very Low | Low | cutaway_textures broken with child unions | Tracked on GitHub | |
Future release |
Task Description
When using cutaway_textures in a CSG object that has union children, results are not as expected; instead, surfaces in the union children that have no explicit texture will be rendered with the default texture instead. This is not the case for e.g. difference children.
Example:
#default { texture { pigment { rgb 1 } } }
camera {
right x*image_width/image_height
location <0,1.5,-4>
look_at <0,1,0>
}
light_source { <500,500,-500> color rgb 1 }
#declare U = union {
sphere { <0,-0.1,-1>, 0.3 }
sphere { <0, 0.1,-1>, 0.3 pigment { color red 1 } }
}
intersection {
sphere { <0,0,0>, 1 pigment { color green 1 } }
object { U }
cutaway_textures
rotate y*90
}
When declaring U as an intersection instead, the results are as expected, with the surface of the first sphere in U being rendered with the texture defined in the outer intersection.
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181 | Backend | Unimp. Feature/TODO | 3.70 beta 40 | Very Low | Medium | Unimplemented, altered or missing features to document ... | Tracked on GitHub | |
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Task Description
This is a list of unimplemented features and things to fix with respect to 3.7 vs 3.6 compatibility. They either need to be fixed in code, or failing that, to be documented prior to release.
Create_INI works differently from 3.6. Prior versions of POV-Ray would write all options to the file, even if they were not supplied by the user (non-supplied options would take the default value). Currently in 3.7, only supplied options are written, because the front-end does not send unused options to the back-end. The proper fix for this would be to have a set of defines that establish the defaults all in one place (currently we rely on hard-coded values scattered around the code), and for the Output_INI_Option() function to look up and use the default when not supplied. As this is not likely to be done before 3.7 release, we need to document it as a temporary situation.
The following messages are marked as ‘currently not supported by code’ in povmsgid.h. We need to check where this comment is correct and if so the docs need to be updated to indicate this (for items that are already documented). Some items may be re-implemented later, and some may never be:
kPOVAttrib_TestAbort
kPOVAttrib_TestAbortCount
kPOVAttrib_VideoMode
kPOVAttrib_Palette
kPOVAttrib_DisplayGammaType
kPOVAttrib_FieldRender
kPOVAttrib_OddField
kPOVAttrib_AntialiasGammaType
kPOVAttrib_LightBuffer
kPOVAttrib_VistaBuffer
kPOVAttrib_DrawVistas
This bug should be edited to add/remove items as time goes by.
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230 | User interface | Feature Request | 3.70 RC3 | Very Low | Low | Improved handling of animations | Tracked on GitHub | |
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Task Description
October to middle November, I prodduced a 5 minutes video mainly py POVRAY.
Here a part of the video.ini file
#
# szenes based on games.pov #
#game-pat #Initial_Frame=450 - time scale 1000 - 30 seconds #Final_Frame=899 #Initial_Clock=-12500 #Final_Clock=17500
#game-lost - time scale 1000 - 22 seconds #Initial_Frame=0 #Final_Frame=659 #Initial_Clock=2000 #Final_Clock=24000
#game-lost - time scale 3000 - 12 seconds - fast through the night #Initial_Frame=0 #Final_Frame=359 #Initial_Clock=24000 #Final_Clock=60000
#book-cover #clock=64000
#game-sunrise - time scale 1000 - 35 seconds #Initial_Frame=0 #Final_Frame=1049 #Initial_Clock=60000 #Final_Clock=95000
Now imagine all the problems:
One computer crashes often because of thermal problems. Last picture rendere 487.
Now calculate the setings, that this computer continues the task at 487
Or 2 computers should render a scene.
Sounds very easy. Something like computer 1 makes 0..499 computer 2 makes 500..999.
But the computers are different in speed and the pictures are very different in computation time.
So it would be best
computer 1: 0 to 999 computer 2: 999 to 0
They would meet in the middle, where ever this middle is.
So it would be much easier with
#game-sunrise - time scale 1000 - 35 seconds Initial_Frame=0 Final_Frame=1049 Initial_Clock=60000 Final_Clock=95000 Initial_Task=487 Final_Task=1049
So I have not to calculate the exact clock seting, when a computer sould continue a task after crashing at picture 487
#game-sunrise - time scale 1000 - 35 seconds Initial_Frame=0 Final_Frame=1049 Initial_Clock=60000 Final_Clock=95000 Initial_Task=1049 Final_Task=0
This would be the reverse calcualtion order. Starting with picture 1049 and going down 1048..1047
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237 | User interface | Definite Bug | 3.70 RC3 | Defer | Very Low | Glitch in displaying rendered pixels and percentage | Tracked on GitHub | |
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Task Description
When rendering in multiple passes (radiosity in my case), the elapsed pixels and percentage, written to terminal are first displayed like this: Rendered 126202 of 360000 pixels (35%) Then on the second stage the output text becomes shorter and you see Rendered 25344 of 360000 pixels (7%)%) The contents of the previous status are not erased, so the longer text persists (note the duplicate percentage sign and closing parenthesis). Such a glitch could have more drastic effect in rare cases.
I’m running Version 3.7.0.RC3 (g++ 4.6.2 x86_64-unknown-linux-gnu) compiled for the Arch Linux package.
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196 | Subsurface Scattering | Definite Bug | 3.70 RC3 | Very Low | Low | More SSLT Caveats | Tracked on GitHub | |
Future release |
Task Description
when a prism is differenced with a primitive (cylinder in this case) if sslt is used it causes a seq fault. Reference distribution file logo.inc and the Povray_Logo_Prism definition.
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227 | Refactoring/Cleanup | Unimp. Feature/TODO | 3.70 RC3 | Very Low | High | Fixed Vector Limitations | Tracked on GitHub | |
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Task Description
See this documentation entry for more details.
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206 | Other | Possible Bug | 3.70 RC3 | Very Low | Low | "Cannot open file" error when text output files specifi... | Tracked on GitHub | |
3.71 release |
Task Description
I created an INI file which specifies the Input_File_Name, Output_File_Name, and also the Render_File and the remaining four text outputs as double-quoted absolute paths on my disk. When I run the render, I get the following output:
Preset INI file is ‘C:\USERS\TPREAL\DOCUMENTS\POV-RAY\V3.7\INI\QUICKRES.INI’, section is ‘[512×384, No AA]’. Preset source file is ‘D:\Ruby\POV-Rb\ini\20110521_004037_Noix.ini’. Rendering with 2 threads. - Cannot open file. Render failed - CPU time used: kernel 0.06 seconds, user 0.02 seconds, total 0.08 seconds. Elapsed time 0.52 seconds.
And the render does not start. The five text output files are not even created, and where the output image should be, there is a file with extension pov-state. The render works as it should only when I remove all five lines defining the five text output files. The paths I specify for the files are correct (paths exist and files do not, no white-spaces or anything), read/write restrictions are disabled in POV-Ray. This used to work in 3.6 and does not work now in 3.7 RC3. The error happens no matter if I run the render using GUI or command line.
(Also please note that the error message is really not useful here, it does not say which file it failed to open, and not even if it was an attempt to open for read or for write.)
I’d be really glad if you could correct this as it’s a critical functionality for me. I’m generating the POV-Ray code automatically and I need to parse the text output automatically to return the status to the generator.
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229 | Image format | Feature Request | 3.70 RC3 | Very Low | Low | Clock value into EXIF data for PNG | Tracked on GitHub | |
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Task Description
The best time for a picture....
I set the day time and so the position of the sun by “clock=”
Normal I document my source very good, but this time, I forgot the clock seting for the picture of my book cover.
So I would find it very practicall to put the clock value and other setings for rendering into EXIF data of the picture.
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202 | Geometric Primitives | Definite Bug | 3.70 RC3 | Very Low | Low | Numerical oddities in Julia_Fractal | Tracked on GitHub | |
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Task Description
I understand that some things have changed in the way certain computations in POV-Ray decide when something is “good enough” and I think this is biting me in Julia_Fractal (where, of course, the highest-resolution computations are needed).
The bug has been posted here:
http://news.povray.org/povray.bugreports/thread/%3Cweb.4dbf2e26b56a53c15b4449250%40news.povray.org%3E/
Including a short .pov file and instructions that reproduce it.
(It pops up in other configurations and view angles as well, but this one captures in in a way that makes it clear it’s a bug: the distance of the camera from the origin appears to change the shape of the rendered object).
This appeared first on a Windows Server 2003 machine, it is apparently confirmable on at least one other system as per that thread.
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222 | Geometric Primitives | Definite Bug | 3.70 RC3 | Very Low | Low | incorrect render of CSG merge with radiosity | Tracked on GitHub | |
Future release |
Task Description
The problem arises when I am trying to trace a radiosity scene without conventional lighting that has a GSG merge object. There are a coincident surfaces, but these surfaces are first merged, then the texture applied. The texture is a simple solig color non-transfluent pigment, default normal, default finish etc..
Problem consists when adding antialiasing, changing resolution, changing camera view-point etc.; when I replace merge with union, the problem disappeared.
The scene was checked on two different machines with different versions of POV-Ray:
Gentoo Linux, kernel 2.6.39-r3, i686 Intel(R) Xeon(TM) CPU 2.80GHz GenuineIntel, 2G RAM (this is Dell PowerEdge 2650 server with 2 dual-core Intel Xeon MP processors); Persistence of Vision™ Ray Tracer Version 3.7.0.RC3 (i686-pc-linux-gnu-g++ 4.5.3 @ i686-pc-linux-gnu)
Gentoo Linux, kernel 2.6.37-r4, x86_64 AMD Athlon™ X2 Dual Core Processor BE-2350, 2G RAM (non-branded machine); Persistence of Vision™ Ray Tracer Version 3.6.1 (x86_64-pc-linux-gnu-g++ 4.4.4 @ x86_64-pc-linux-gnu)
(scene has been adapted slightly to be rendered with 3.6, the adaptation was to change “emission” with “ambient” and replace gamma “srgb” with “2.2”)
Both machines generate similar images.
The attachment is an archive containing sources of minimal scenes with these problems, and sample pictures I generated from them on my machines.
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226 | Geometric Primitives | Possible Bug | 3.70 RC3 | Very Low | Low | Near-coincident surface accuracy | Tracked on GitHub | |
|
Task Description
This is a transparent box very close to a plane.
box {
-1, 1
pigment { rgbf <0, 0, 1, 1> }
}
plane {
#if (version < 3.7)
y, -1.0000007
#else
y, -1.00007
#end
pigment { rgb 1 }
finish { ambient 1 }
}
camera {
location <1, 2, 3>
look_at 0
}
The box is placed 100 times closer to the plane for 3.6, but both 3.6 and 3.7 produce exactly the same black artifact (attached).
So apparently 3.7 is less accurate. (And the exact factor 100 feels suspicious.)
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240 | Geometric Primitives | Feature Request | 3.70 RC3 | Very Low | Low | Object for efficient automatic periodic pavement | Tracked on GitHub | |
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Task Description
Whenever some object is to be periodically repeated in some kind of grid, you can achieve this with macros, but it a) wastes a lot of resources
even if object references are implemented in the future, wrapper with its own transformation matrix still takes space and bookkeeping
b) is not infinite
annoying when making infinite planar tiling with arbitrary objects
like an approximate water surface or tiling with real bricks
or anything that needs to extend to horizon
c) is not optimized for periodicity
I think it can be very efficiently implemented as an object that takes a finite object argument (like CSG functions) and can be periodic in either 1D,2D or (possibly dangeorous?) 3D with specified period. In each dimension, the number of repetitions can be any integer or even infinity (or max_int). Something like periodicity <2,2,Infinity> 2 copies in 1 direction, 2 in the other, infinite in the third grid_separation <1,2,2> 1 unit size in first direction, 2 unit sizes in the other two
All the code needs to do is raytrace in the current unit cell and if the ray passes uninterrupted, pass it through the neighbouring unit cell (which means trace a translated ray through the same object). The object itself would just feel an additional clipping box, everything else would work seamlessly.
In case of infinite column of transparent object, max_trace stops the infinite loop anyway.
This is just a suggestion, I realize this is more of a long-term change but it is quite easy to implement and would simplify a large number of projects.
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205 | Documentation | Unimp. Feature/TODO | 3.70 RC3 | Very Low | Low | Syntax documentation uses inconsistent notation | Tracked on GitHub | |
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Task Description
The syntax notation used in the main documentation is different than that used in the quick-reference section. This should be changed for consistency, using the superior quick-reference notation throughout.
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256 | Texture/Material/Finish | Feature Request | 3.70 RC6 | Very Low | Low | CSG texturing modes | Tracked on GitHub | |
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Task Description
At times, the current method of specifying texture for CSG components and compounds is restricting. The issue pops up now and then, see e.g.
http://news.povray.org/povray.pov4.discussion.general/thread/%3Cweb.4799def8e1857b77c150d4c10%40news.povray.org%3E/
http://news.povray.org/povray.general/thread/%3Cweb.4fc892634f065c00e32b83540@news.povray.org%3E/
http://news.povray.org/povray.general/thread/%3Cweb.5073e9f7dae1fbb2d97ee2b90%40news.povray.org%3E/
There should be a new CSG option “texture_mode” or similar, which could take one of the following values:
preserve (the current behavior) cutaway (the current behavior when specifying cutaway_textures) override (replace all individual textures with compound texture) layer (layer the compound texture over the existing textures)
and possibly, more involved
modify/merge: if both element and compund textures are simple, i.e. not layered or mapped, override all default values of the element textures with the values from the compound texture. The idea would be to, e.g., have the elements already pigmented but then apply common normal or finish properties.
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269 | Texture/Material/Finish | Possible Bug | 3.70 RC6 | Very Low | Low | Transparent Objects inside Media Cause Artefacts | Tracked on GitHub | |
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Task Description
When placing a transparent object inside another object which contains media, artefacts may occur (see attached file). They look similar to specular highlights or are just strange white spots in the image.
I discovered artefacts of that kind first in the image of which MediaArtefactDetail.png is a cropped part. The code I managed to reproduce such artefacts with contained a “starfield” sphere
sphere {
<0,0,0>, 1
pigment { rgbt 1 }
interior {
media {
emission rgb 1/10
density {
crackle form <1,0,0>
density_map {
[0.0 rgb 1]
[0.05 rgb 0]
}
scale 0.002
}
}
}
scale 1000
hollow on
}
and a transparent sphere
sphere {
<0,0,0>, 1
pigment { rgbt 1 }
scale 2
hollow on
}
which is, obviously, completely inside the other sphere. So is the camera.
Since the sphere has a pigment { rgbt 1 }, it should be completely invisible, which is correctly rendered as long as the scaling factor is 1 and hollow off (MediaArtefact1.png). Changing hollow to on does not yet produce the artefact, but the right half of the output image seems to be shifted by one pixel (MediaArtefact2.png). Changing the scaling factor to 2 (as it is in the above code) produces the artefact (MediaArtefact3.png). Changing the camera location (MediaArtefact4.png) does not change anything, the artefact just “moves with the sphere”. Changing the sphere size again, however, seems to stir up the “stars” in the “starfield” sphere while not removing the artefacts (MediaArtefact5.png). Changing hollow to off again does neither (MediaArtefact6.png).
The artefacts are definitely no specular highlights. There is not even a light source in the scene that could produce any. I used POV-Ray 3.7 RC6 to render the images, but the artefact shown in MediaArtefactDetail.png already occured in POV-Ray 3.6 which I used to render that image.
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252 | Photons | Definite Bug | 3.70 RC6 | Very Low | Low | photons and light_group is broken | Tracked on GitHub | |
|
Task Description
photons are not working when used with a light_group. verified in NG posting in p.general a simple scene file is attached.
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264 | Photons | Unimp. Feature/TODO | 3.70 RC6 | Defer | Low | Improve precision of photon direction information | Tracked on GitHub | |
|
Task Description
In the photons map, the direction of each photon is stored as separate latitude & longitude angles (encoded in one byte each), causing the longitudinal direction component’s precision to be unnecessarily high for directions close to the “poles” (Y axis); in addition, encoded value -128 is never used. For better overall precision as well as precision homogenity, the following scheme could be used instead:
latCode = (int)((LatCount-1) * (lat/M_PI + 0.5) + 0.5)
For each latitude code, define a specific number of encodable longitude values, LngCount[latCode] = approx. cos(lat)*pi*65536/(2*LatCount); this can be a pre-computed table, and may need slight tweaking for optimum use of the code space. Encode the longitude (-pi to +pi) into a value from 0 to (LngCount[lat]-1) using
LC = LngCount[latCode];
lngCode = (int)(LC * (lng/(2*M_PI) + 0.5) + 0.5) % LC;
dirCode = LatBase[latCode] + lngCode;
For decoding, a simple lookup from a precomputed list of directions could be used (2^15 entries, i.e. one hemisphere, will suffice). To conserve space, direction vectors could be scaled by (2^N-1) and stored as (N+1)-bit signed integer triples rather than floating point values; due to the limited precision of the lat/long information, 8 bits per coordinate might be enough, giving a table size of 96k. A full double-precision table would require 786k instead.
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251 | Parser/SDL | Possible Bug | 3.70 RC6 | Very Low | Medium | Scene / include files of >2GB size may cause problems | Tracked on GitHub | |
3.71 release |
Task Description
Code inspection shows that we’re still using fseek() and ftell() in various places (including text file input), which can’t handle file positions of 2GB and beyond (except on 64-bit linux machines); those calls need to be examined and (where appropriate) replaced with the fseek64() macro we’re already defining (but currently not using), and a to-be-defined ftell64() macro.
One potential (untested) error scenario would be a scene file calling a macro that is defined at the end of a > 2GB long include file.
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263 | Parser/SDL | Feature Request | 3.70 RC6 | Very Low | Low | Functions and patterns for finish variations | Tracked on GitHub | |
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Task Description
the pigment {} and normals {} sections allow spatial variation of color, transparency and normal map. On the other hand, the specular parameter is a fixed scalar. This removes many possibilities. For instance, specularity could vary in space (speckles of oil or water on a surface, worn-out finish, having specularity reduce where the pigment transparency increases) and have color components. With current settings, the light’s color is simply multiplied by the scalar specified by “specular”, whereas multiplying each component with different color could create diverse effects (the “metallic” keyword already acts similar to duplicating the specular color from the pigment). The syntax could be exactly the same as for the pigment (all the patterns, color maps, image maps and functions would apply, allowing reuse of most of the code).
The effect can now be partially faked by having patterned textures, but it requires a very complex code and the lack of layering of patterned textures makes it difficult to vary the specularity and pigment separately.
In a similar way, roughness and brilliance could also vary in space.
Doing the same for varying reflectivity would be more difficult, as it has angular dependence and possibilty of Fresnel calculation, but it could at least be a full color instead of a simple scalar multiplier. For instance, having a blue surface that reflects only red component of the light should not be impossible.
I think at least part of this functionality actually makes the scene description language more uniform and self-consistent.
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246 | Other | Possible Bug | 3.70 RC6 | Very Low | Low | Regression on scale limit between 3.7 and previous rele... | Tracked on GitHub | |
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Task Description
From Thomas de Groot
Using the following code for a (sky) sphere in a scene, with light source well outside the sphere; works correctly until the above scale value. Use a value of >=100*10e4 and the sphere becomes black.
#version 3.7;
global_settings{ assumed_gamma 1.0 }
#declare T_sky =
texture {
pigment {
gradient y
pigment_map {
[0.0 srgb <1.0,0.7,0.6>*1 transmit 0.5]
[1.0 srgb <0.8,0.1,0.0>*1 transmit 0.5]
}
}
finish {
emission 0.9
diffuse 0.0
}
}
#declare T_cosmos =
texture {
pigment {
color rgbt <0,0,0,1>
}
finish {
ambient 0.0
diffuse 0.0
}
}
sphere {
<0,0,0>,1
texture {T_sky}
interior_texture {T_cosmos}
no_shadow
no_reflection
inverse
scale 99.9*10e4
}
Working with windows version of POV-Ray and Win7 x64
Is this normal for version 3.7 RC5? I seem to remember that with lower versions of POV-Ray on could go at least to 10e6. Especially with the Ringworld scenes back in 2010 the scales used where much larger without any black out.
I can indeed confirm that the Ringworld scene does not render correctly anymore, with identical black out.
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272 | Other | Feature Request | 3.70 RC6 | Defer | Very Low | Minor change, significant speedup in cubic polynomial s... | Tracked on GitHub | |
3.71 release |
Task Description
While familiarizing myself with the code, I found some small changes in the solve_cubic function that lead to a significant speedup.
In my experience, “pow” is by far the slowest function in math.h and replacing it with simpler functions usually makes a tremendous impact on the speed (it’s an order of magnitude slower than sqrt/exp/cbrt/log).
solve_cubic has a “pow” function that can be replaced by cbrt (cubic root), which is standard in ISO-C99 and should be available on all systems. Separate benchmarks of solve_cubic function show this change almost doubles the speed and does not lower the accuracy. As solve_cubic is part of the solution of quartic equation, this improves the speed for many primitives. Testing with a scene containing many torus intersection tests (attached below) I still observed almost 10% speedup (Intel, 4 threads, 2 hyperthreaded cores, antialiasing on, 600×600: from 91 to 84 seconds). And this is for a torus, where a lot of time is spent in the solve_quartic and cubic solver is only called once! Similar speedup should be expected for prism, ovus, sor and blob.
I do believe the cubic solver can be done without trigonometry, but that would mean changing the algorithm, introducing new bugs and requiring a lot of testing. However, the trigonometric evaluation can still be simplified (3% speedup in full torus benchmark).
These changes don’t affect the algorithm at all, they are mathematically identical to the existing code, so the changes can be applied immediately. I also included other changes just as suggestions. Every change is commented and marked with [SC 2.2013].
This sadly does not speedup the sturm solver, which uses bisection and regula-falsi and looks very optimized already.
The test scene I used has a lot of torus intersections from various directions (shadow rays, main rays, transmitted rays).
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273 | Other | Definite Bug | 3.70 RC6 | Very Low | Medium | No automatic backup files from inc files | Tracked on GitHub | |
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Task Description
If enabled, POVray always created backups of pov and inc files once per session. Now using 3.7 RC6 only pov file backups are created but not from inc files.
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293 | User interface | Possible Bug | 3.70 RC7 | Very Low | Low | POV-Ray Shown Twice in Windows Taskbar | Tracked on GitHub | |
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Task Description
When rendering for some time, it occasionally happens that POV-Ray appears twice in the Windows taskbar. One button is the normal one, the other one does not open any window when clicked on and reads something like “99% complete” (see attached image), like the render window’s title, but obviously unrelated to it (probably the title the render window had shortly before?). After stopping the render, the odd taskbar button remains there until POV-Ray is closed.
Observed under Windows XP
POV-Ray 3.7.0.RC7.msvc10-sse2.win32
When applications are summarized into groups in the taskbar by Windows, the odd POV-Ray button is attached to the Windows Explorer group
Run with render priority set to “high”
Is this a Bug in Windows or in POV-Ray?
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295 | User interface | Definite Bug | 3.70 RC7 | Very Low | Low | Minor GUI Bugs | Tracked on GitHub | |
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Task Description
Here are two low-priority bugs in POV-Ray’s GUI, observed by me under Windows XP, which should be easy to fix I think:
In the “Insert” menu, there are sub-menus (e.g. “Radiosity and Photons”) in which there are menu seperators at the end of the popped-up menu bar.
The progress bar in the top-right corner of the editor window seems to be too large for the window (203px) and therefore clipped. As a result, progress seems to be 100% when it is not yet, e.g. at 90% progress. (Have not measured exactly.)
Both bugs are not severe at all, but it would be nice if they could be fixed. By the way, a second progress bar could be added to visualize the number of frames already rendered in an animation.
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286 | Texture/Material/Finish | Possible Bug | 3.70 RC7 | Very Low | Low | reflection exponent other than 1 causes black artifacts... | Tracked on GitHub | |
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Task Description
[EDIT: Original title was “radiosity causing black patches when using emission less than 0”]
see attached image for reference.
mountain on left has emission set to -.13 and black patches show up, when emmission set to 0 or greater no patches
changing max_trace or any radiosity settings has no effect
setting no_radiosity on mountain fixed problem as a temp fix
code sample ...
#version 3.7;
#default { finish { ambient 0 } }
#declare rad_lvl = 4;
global_settings {
assumed_gamma 1
max_trace_level max(5,rad_lvl*3)
adc_bailout .007
ambient_light 0
radiosity {
pretrace_start 64/max(image_width,image_height)
#if(rad_lvl)
pretrace_end max(2,int(8/rad_lvl))/max(image_width,image_height)
#else
pretrace_end 32/max(image_width,image_height)
#end
count pow(rad_lvl+1,2)*10
nearest_count 1
#if(rad_lvl) error_bound 1/rad_lvl #end
low_error_factor max(.4,(8-rad_lvl)/10)
recursion_limit 1
gray_threshold .25
brightness 1
max_sample 1
normal on
media off
always_sample off
minimum_reuse min(.008,8/max(image_width,image_height))
maximum_reuse .1
adc_bailout .02
}
}
#declare sunC = rgb <1, 1, .9925>; // actual D65 standard illuminant
#declare SkyC = rgb <.3195, .5745, .8805>;
#macro GammaAdj(C,G) rgb <pow(C.red,G),pow(C.green,G),pow(C.blue,G)> #end
light_source {
50000*y
sunC*1.06
area_light <-300, 0, -300>, <300, 100, 300>, 3, 3
rotate <-28, 0, 14>
adaptive 0
circular
}
sphere { 0, 1
texture {
pigment{
gradient y
pigment_map{
[.07 GammaAdj(SkyC,.5)]
[.2 average pigment_map { [.5 GammaAdj(SkyC,.75)][1 wrinkles turbulence .65 octaves 5 lambda 3 omega .9 color_map { [.2 rgb 1][.5 SkyC] } scale <10, .1, 1>] }]
[.4 GammaAdj(SkyC,1.15)]
[.5 GammaAdj(SkyC,1.35)]
}
rotate -75*y scale <1, 1, 100>
}
finish { diffuse .72 }
}
scale 100000
inverse
}
#declare Cam_pos = Cam_pos + <0, 20, -40>;
#declare Cam_lkt = Cam_lkt + <0, 10, 50>;
camera {
location Cam_pos
direction <0,0,1>
right 1.33*x
up y
sky <0,1,0>
#if(Cam_agl) angle Cam_agl #end
look_at Cam_lkt
}
#macro sinai(HillQ)
#local F = function { pattern { granite poly_wave 4 turbulence .01 lambda 2.1 omega .9 scale 5 translate <.2, 0, 18.08> scale <2, 1, 3> } }
#local N = function { pigment { crackle ramp_wave turbulence .3 lambda 2.2 omega .76 color_map {[0 rgb 0][1 rgb 1] } scale .07 translate <-.15, -.12, .13> } }
height_field {
function HillQ, HillQ { F(x,y,z) + N(x,y,z).grey/47 }
water_level .05
clipped_by { box { <0, .05, .3>, <1, 1, 1> } }
translate <-.5, -.05, -.5>
rotate 20*y
texture {
pigment{ crackle color_map { [0 rgb <161, 107, 71>/255][.25 rgb <193, 132, 93>/255][.35 rgb <218, 163, 123>/255][.45 rgb <212, 153, 112>/255][.55 rgb <222, 166, 125>/255][.65 rgb <236, 178, 124>/255][.75 rgb <220, 154, 102>/255][.85 rgb <160, 121, 103>/255] } turbulence .75 lambda 3 omega .7 scale .1 }
finish{ diffuse albedo .56 emission -.13 specular .25 roughness .02 brilliance 1.5 metallic 1.3 }
normal { crackle poly_wave .7 turbulence .4 omega .8 scale <.007, .03, .007> }
}
rotate 12*y
scale <2400, 2000, 3000>*1.5
translate <1900, 0, 1900>
scale <-1,1,1>
no_radiosity
}
#end
sinai(1600)
plane { y,0 pigment { rgb <1, 1, 1> } }
//courtyard gating not included due to size of code and many external files needed. add anything around <0,0,0> to try to reproduce effect of error
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306 | Subsurface Scattering | Definite Bug | 3.70 RC7 | Very Low | High | finish subsurface block before global_settings subsurfa... | Tracked on GitHub | |
3.71 release |
Task Description
The following scene causes a crash:
sphere {
<0,0,0>, 1
finish { subsurface { translucency 1.0 } }
}
global_settings {
subsurface { }
}
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299 | Parser/SDL | Feature Request | 3.70 RC7 | Very Low | Low | Object Properties Feature | Tracked on GitHub | |
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Task Description
Up to POV-Ray 3.7 RC7 it has not been possible so far to declare custom properties for POV-Ray’s objects, which would be especially useful for complex objects defined in include files.
Currently, if you want to have an object (e.g. a car) with certain variable parameters (e.g. colour, wheel rotation, ...) defined in an include file and the parameters set by a scene file which uses the include file, you have to choose one of the following approaches:
1. use a macro
#macro car(colour, wheelrot, ...)
...
#end
or, 2. check parameters declared before, e.g.
#declare car =
union {
#ifdef (colour)
#local colour_internal = colour;
#else
#local colour_internal = default_colour;
#end
}
The resulting object would be used in the following way:
#include "car.inc" // include file once
object {
car(rgb <1,0,0>, 0, ...) // macro approach
}
// other approach
#declare colour = rgb <1,0,0>;
#declare wheelrot = 0;
...
#include "car.inc" // include file every time you want to have a car object instance
object {
car
}
Needless to say, both approaches are not quite optimal.
The macro approach needs only one #include directive and name conflicts will (hopefully) not be a problem. However, one would have to look up the parameter order of the macro in the include file, in the worst case every time the macro is used.
The other approach needs as many #include directives as car objects shall be instantiated, there can arise name conflicts with other inculde files used in the scene, and a (potentially long) list of parameters has to be declared before each #include. On the other hand, with this approach for any value it is clear which information it gives, e.g. #declare colour = rgb <1,0,0> can easily be read as ‘set car colour to “red”‘.
My suggestion would be creating an SDL feature to
One step up could be to even declare object classes along with them.
This could look like this:
// include file code
class car { // alternatively (without classes) use #declare car = object { ...
property colour = rgb <1,0,0>; // with default colour
union {
...
}
}
// scene file code
car { // alternatively (without classes) use object { car ... }
colour rgb <0,0,1>
}
Note that this solution makes the declarations much more concise and easy-to-read. Especially in scenes with many includes and animation scenes where objects’ properties have to be manipulated according to sometimes complex functions, this would be very useful. Please also consider that such user-defined objects can have dozens of properties.
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309 | Parser/SDL | Definite Bug | 3.70 RC7 | Very Low | Low | Warning Message Missing | Tracked on GitHub | |
3.71 release |
Task Description
Draw_Vistas, Light_Buffer, and Vista_Buffer (plus associated switches) do not issue warning when used, even tho code has been disabled.
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300 | Other | Feature Request | 3.70 RC7 | Defer | Very Low | Reference Documentation Support | Tracked on GitHub | |
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Task Description
As emerged as an idea during the discussion of FS#299, an SDL / POV-Ray editor feature would be useful that allows API documentation via formal comments, e.g. in include files:
/**
* Creates a car object.
* @param a
* description of param a
* ...
*/
#macro car(a,b,c)
...
#end
In addition to the ability of (auto-)generating a documentation file from such comments, an editor window feature would be convenient that allows popup display of a macro’s (object’s / parameter’s / ...) documentation section.
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301 | Other | Definite Bug | 3.70 RC7 | Very Low | Low | Fallback to default image size causes wrong values to b... | Tracked on GitHub | |
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Task Description
When resolution is not specified (neither via POVRAY.INI nor via QUICKRES.INI nor via command line or custom .ini file), random values are displayed for image resolution in the Image Output Options message output. (The actual render will be performed at the default size of 160×120 pixels though.)
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302 | Other | Possible Bug | 3.70 RC7 | Very Low | Low | confusing error message when .ini file cannot be parsed | Tracked on GitHub | |
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Task Description
When a command-line parameter in an .ini file cannot be parsed (such as “+a.3”), POV-Ray reports a “Problem with setting”, quoting the command line, rather than indicating that the problem occurred in an .ini file. This leads the user to think that the problem is with the command line itself, unnecessarily confusing him.
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303 | Other | Definite Bug | 3.70 RC7 | Defer | Very Low | wrong bit depth reported for OpenEXR file format | Tracked on GitHub | |
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Task Description
When using OpenEXR output file format, POV-Ray erroneously reports it as “24 bpp EXR” in the message output, while in fact it generates a 3×16 = 48 bpp file.
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275 | Light source | Definite Bug | 3.70 RC7 | Very Low | Low | circular area lights exhibit anisotropy | Tracked on GitHub | |
Future release |
Task Description
circular area lights exhibit some anisotropy, being brighter along the diagonals than on average, as can be demonstrated with the following scene:
//+w800 +h800
#version 3.7;
global_settings{assumed_gamma 1}
plane{-z,-10 pigment{rgb 1} finish{ambient 0 brilliance 0}}
disc{0,z,10000,0.5}
camera{orthographic location z look_at 10*z up y*12 right x*12}
light_source{-10*z rgb 10 area_light 10*x 10*y 257 257 adaptive 4 circular}
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287 | Light source | Definite Bug | 3.70 RC7 | Very Low | Low | area_illumination shadow calculation | Tracked on GitHub | |
Future release |
Task Description
not sure if this is something needing further work or an intended effect.
Shadows from and area light with area_illumination on seem to follow the same shadow calculation as a standard area light by giving more weight to lights near the center of the array. I would assume the shadows would be calculated similarly to individual lights in the same pattern as the array by evenly distributing the amount of shadow equally for each light. But this is not what I see.
The code sample below when rendered with scene 1 will show shadows grouped near the center from the area light with area_illumination. If scene 1 is commented out and scene 2 is uncommented then rendered, you will see evenly distributed shadows from individual lights. Area lighting with area_illumination I would assume should give a result identical to scene 2. If scene 1 is rendered with area_illumination off, the shadow calculation is exactly the same as with area_illumination on.
example images rendered on win32 XP
#version 3.7;
global_settings {
ambient_light 0
assumed_gamma 1
}
camera {
location <0, 3, -5>
look_at <0, 2, 0>
}
background { rgb <.3, .5, .8> }
plane { y,0 pigment { rgb .7 } }
torus { 1.5,.1 rotate 90*x translate 4*z pigment { rgb .2 } }
plane { -z,-7 pigment { rgb .7 } }
/*
// scene 1
light_source{
y
1
area_light 3*x, z, 7, 1
area_illumination on
}
union {
sphere { 0,.05 }
sphere { .5*x,.05 }
sphere { x,.05 }
sphere { 1.5*x,.05 }
sphere { -.5*x,.05 }
sphere { -x,.05 }
sphere { -1.5*x,.05 }
translate y
hollow pigment { rgbt 1 } interior { media { emission 10 } }
}
// end scene 1
*/
// scene 2
#declare Light = light_source {
0
1/7
looks_like { sphere { 0,.05 hollow pigment { rgbt 1 } interior { media { emission 10 } } } }
}
union {
object { Light }
object { Light translate .5*x }
object { Light translate x }
object { Light translate 1.5*x }
object { Light translate -.5*x }
object { Light translate -x }
object { Light translate -1.5*x }
translate y
}
// end scene 2
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289 | Light source | Possible Bug | 3.70 RC7 | Very Low | Low | area_illumination with light fading and scattering medi... | Tracked on GitHub | |
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Task Description
with reference to http://bugs.povray.org/task/46
still some issue with area illumination and light fading when interacting with media
seems light fade is not taken into account with scattering media. emission and absorption media seem to work fine. occurs with all scattering types.
#version 3.7;
global_settings {
ambient_light 0
assumed_gamma 1
}
camera {
location <0, 3, -5>
look_at <0, 2, 0>
}
#declare Light = 3; // light 1 = individual lights
// light 2 = standard area light
// light 3 = area light with area illumination
#declare Fade = 1; // light fading: 1 on, 0 off
#declare Media = 1; // media 1 = scattering
// media 2 = emission
// media 3 = absorption
#declare Type = 1; // scattering media type
#switch(Light)
#case(1)
#declare Ls = light_source {
0
1/7
#if(Fade) fade_distance 2 fade_power 2 #end
}
union {
object { Ls }
object { Ls translate .5*x }
object { Ls translate x }
object { Ls translate 1.5*x }
object { Ls translate -.5*x }
object { Ls translate -x }
object { Ls translate -1.5*x }
translate y
}
#break
#case(2)
light_source{
y
1
area_light 3*x, z, 7, 1
#if(Fade) fade_distance 2 fade_power 2 #end
}
#break
#case(3)
light_source{
y
1
area_light 3*x, z, 7, 1
#if(Fade) fade_distance 2 fade_power 2 #end
area_illumination on
}
#break
#end
cylinder { <0, .01, 0>, <0, 5, 0>, 2 pigment { rgbt 1 } hollow no_shadow
interior {
media {
#if(Media = 1) scattering {Type, 30 } #end
#if(Media = 2) emission 2 #end
#if(Media = 3) absorption 2 #end
density { cylindrical turbulence 1.5 scale <1, .14, 1> }
}
}
scale <.15, 1, .4> translate 4*z
}
plane { y,0 pigment { rgb .7 } }
plane { -z,-7 pigment { gradient y color_map { [.5 rgb 1][.5 rgb 0] } } }
union {
sphere { 0,.05 }
sphere { .5*x,.05 }
sphere { x,.05 }
sphere { 1.5*x,.05 }
sphere { -.5*x,.05 }
sphere { -x,.05 }
sphere { -1.5*x,.05 }
translate y
hollow pigment { rgbt 1 } interior { media { emission 10 } }
}
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281 | Geometric Primitives | Feature Request | 3.70 RC7 | Defer | Low | Bug in rendering of Bézier patches | Tracked on GitHub | |
Future release |
Task Description
In version 3.7.0.RC7.msvc10.win64, there is a bug in rendering Bézier patches in which four points (along one edge) are all the same point.
The rendering can be seen here: http://i.imgur.com/eq2UIXR.png [Edit: See attachment for the rendering]
As you can see, there is a visible unwanted artifact in the corner of each patch. The two patches shown are essentially the same, except with the 4×4 matrix of vertices transposed (just to demonstrate that simply transposing it didn’t fix it).
Expected rendering is a smooth surface without the artifact.
Below is the code used to render the above example.
#version 3.7;
global_settings { assumed_gamma 1.0 }
camera {
location <45, 31, -10>
look_at <40, 21, 200>
right x*image_width/image_height
}
light_source {
<660, 300, -525>
color rgb 1
}
Example 1: First point in each row is the same point bicubic_patch { type 1 flatness 0.001 u_steps 4 v_steps 4 <32.2168, -23.78125, 0>, <34.4968, -23.78125, 0>, <35.2168, -23.78125, -0.72>, <35.2168, -23.78125, -3>, <32.2168, -23.78125, 0>, <34.4968, -22.10256, 0>, <35.2168, -21.57244, -0.72>, <35.2168, -21.57244, -3>, <32.2168, -23.78125, 0>, <33.9709, -21.55577, 0>, <34.52483, -20.85299, -0.72>, <34.52483, -20.85299, -3>, <32.2168, -23.78125, 0>, <32.30556, -21.50298, 0>, <32.33359, -20.78352, -0.72>, <32.33359, -20.78352, -3> rotate 180*x
scale 1.4 translate ←5, 0, 0> pigment { color <1, 0, 0> } }
Example 2: First row is all the same point bicubic_patch {
type 1 flatness 0.001
u_steps 4 v_steps 4
<32.2168, -23.78125, 0>, <32.2168, -23.78125, 0>, <32.2168, -23.78125, 0>, <32.2168, -23.78125, 0>,
<34.4968, -23.78125, 0>, <34.4968, -22.10256, 0>, <33.9709, -21.55577, 0>, <32.30556, -21.50298, 0>,
<35.2168, -23.78125, -0.72>, <35.2168, -21.57244, -0.72>, <34.52483, -20.85299, -0.72>, <32.33359, -20.78352, -0.72>,
<35.2168, -23.78125, -3>, <35.2168, -21.57244, -3>, <34.52483, -20.85299, -3>, <32.33359, -20.78352, -3>
rotate 180*x
scale 1.4
pigment { color <1, 1, 0> }
}
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288 | Geometric Primitives | Possible Bug | 3.70 RC7 | Very Low | Low | Tolerance problem with refraction in blobs in CSG inter... | Tracked on GitHub | |
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Task Description
If a blob is intersected by something else, the composite object has incorrect refractions if it is too small (in absolute units). Having the same object constructed without a blob, the errors happen at much smaller scales. The errors don’t affect solid objects, just refractions.
An example shows a half-sphere, constructed as CSG sphere + plane, and identical half-pshere, constructed as CSG blob + plane. When the scale of the entire construction is changed, the refractions disappear first for the blob, and at 100x times smaller scale, also for the sphere. The right side shows the solid version, showing that the surface intersection test is ok, it’s just the refraction that fails.
The problem is not present when looking from the curved side (the blob side). So the ray that hits the blob, gets refracted correctly, but the ray that hits the intersecting plane first, and should then refract in the blob from the inside, doesn’t work. If in attached sphere, you exchange -y with y in clipping planes, everything is ok.
The scale when this happens is not very small - blobs of radius 0.02 already fail (noticed because in 1=1metre scale, blob raindrops on a glass plate didn’t have intersections when looking from the back).
Examples are named by factor=9,0.9,0.09,0.009 and you can see first the blob (top) refraction gets smaller and disappears, then later the bottom (sphere) also gets the same problem.
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292 | Geometric Primitives | Unimp. Feature/TODO | 3.70 RC7 | Very Low | Low | Arbitrary containing object for isosurfaces | Tracked on GitHub | |
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Task Description
A low priority thought for the future: isosurface now only allows contained_by to be a sphere or a box. It would be more intuitive to allow the same objects that are allowed in clipped_by and bounded_by (although it probably needs to be finite). It would enable allow much faster rendering in many cases:
1) There are a lot of cases when the sphere or a box are very bad in bounding - if an object has a hole, a torus may be better, and in many cases, cylindrical bounding would help a lot. 2) Sometimes, having a too large contained_by object includes far-away parts of the iso-function, and expose large gradients that you want to avoid. If a bounding object is better, you can decrease the max_gradient and speed up the render. 3) The isosurface is usually much more expensive to calculate than any normal bounding object, so it’s an improvement even if the intesection test is not as fast as bounding box. 4) A typical case: if you use texture-like functions to make the surface realistically rough, you know almost exactly what the bounding object is - it can be the original unmodified object. 5) For isosurface terrains, a preprocessing macro could create a rough mesh-like bounding object to contain the “mountains”, thus making everything faster. 6) In case you want clipping, having the contained_by set to the same object probably avoits calculating too many intersections.
The main modification is probably that the intersections of bounding objects can be split into more than one interval - but it’s probably worth it, the isosurfaces are usually a speed bottleneck.
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