POV-Ray

The Persistence of Vision Raytracer (POV-Ray).

This is the legacy Bug Tracking System for the POV-Ray project. Bugs listed here are being migrated to our github issue tracker. Please refer to that for new reports or updates to existing ones on this system.

IDCategoryTask TypeReported InPrioritySeverity  descSummaryStatusProgressDue In Version
91Texture/Material/FinishFeature Request3.70 beta 36DeferLowSlope pattern applied to object is not transformed afte...Tracked on GitHub
0%
Future release Task Description

There is an big issue with the slope pattern: when the object it is applied to is instanced (again) with a transformation (in particular a rotation, as a translation would not impact.. but a shear might), the colours of the surfaces are changed.

  
object { p translate -5*x }
object { p rotate 220*y+20*x    translate 3*x }       

Nobody would expect the object to be different in appearance.
If slope {} is replaced with wood, all is fine. (as for others textures, i guess)

IMHO, the slope vector need to be adjusted for the later transformation(s) (so as to compensate the issue of using the Perturbed Normal vector).

This should not impact the AOI/FACING (experimental) patterns, as AOI definition is pretty clear about duplicating & transform if you think about it a bit, as well as FACING: for these two, it is expected to either use the ray(current point of view) or a fixed 3D point as reference. At the limit, discussion about moving the 3D point of FACING might also be opened to interpretation.

AOI/FACING are in task #19

96Texture/Material/FinishFeature RequestNot applicableVery LowLowUser-defined warpsTracked on GitHub
0%
Future release Task Description

User-defined warps would be nice to have, something along the lines of:

warp {
  function { MyFnX(x,y,z) } // function to compute pattern-space x-coordinate from object-space <x,y,z> coordinate
  function { MyFnY(x,y,z) } // ditto for pattern-space y coordinate
  function { MyFnZ(x,y,z) } // ditto for pattern-space z coordinate
}

// a displacement warp:
warp {
  function { x + MyFnX(x,y,z) }
  function { y + MyFnY(x,y,z) }
  function { z + MyFnZ(x,y,z) }
}
108Parser/SDLFeature Request3.70 beta 37Very LowLowmotion_blur feature similar to Megapov versionTracked on GitHub
0%
Future release Task Description

motion_blur which is a simple and effective feature to use in Megapov to simulate motion blur of, e.g. bird wings, propellers or running animals, would be a neat addition to version 3.7 and later.

In Megapov, the feature requires a line of code in the global_settings{} e.g.: motion_blur 10, 2
and a declaration for the moving object. e.g.:

motion_blur {
  type 0
  object{MyObject  material{MyMaterial rotate x*clock*2}}
  rotate x*clock*10
}

type represents several types of pre-defined motions.

Thanks,

Thomas

115Texture/Material/FinishFeature Request3.70 beta 37aVery LowLowMore cutaway_texturesTracked on GitHub
0%
Future release Task Description

Think this is still a problem. See the attached scene file. Find the WindowFrameSegment declaration for more info. The scene as-is shows the problem (SOME portions of the difference inherit the color of the room) the window opening is scaled larger to show that they AREN’T touching. The problem goes away when (in WindowFrameSegment) the 1st occurrence of the applied texture is commented out and the 2nd occurrence is uncommented, and cutaway_textures is commented out.

118Light sourceFeature Request3.70 beta 37aVery LowLowMore efficient handling of fading lightsTracked on GitHub
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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.

127Parser/SDLFeature Request3.70 beta 37aVery LowLowExpandable arraysTracked on GitHub
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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.

131OtherFeature Request3.70 beta 37aVery LowLowAbility to change the order of editor tabs by dragging ...Tracked on GitHub
0%
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.

138User interfaceFeature Request3.70 beta 37aVery LowLow"Rename" option in File menuTracked on GitHub
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Task Description

Would be great if there were a “Rename” option in the editor File menu to rename the current file name. Otherwise, you have to close the file, rename it in file manager, then open the file again, thus loosing the current tab position and undo history for the file.

140Platform-specificFeature Request3.70 beta 37aVery LowLow"Reload" option in File menuTracked 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.

142Texture/Material/FinishFeature Request3.70 beta 37aVery LowLowcamera_view pigment from MegaPOVTracked on GitHub
0%
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!

145Parser/SDLFeature Request3.70 beta 37aVery LowLowStack trace report on errorTracked on GitHub
10%
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.

177Light sourceFeature Request3.70 beta 39Very LowLowAdd support for conserve_energy to shadow computationsTracked 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
}
178Texture/Material/FinishFeature Request3.70 beta 39Very LowLowModify metallic reflection code to better work with con...Tracked on GitHub
0%
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
}
229Image formatFeature Request3.70 RC3Very LowLowClock value into EXIF data for PNGTracked on GitHub
0%
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.

230User interfaceFeature Request3.70 RC3Very LowLowImproved handling of animationsTracked on GitHub
0%
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

240Geometric PrimitivesFeature Request3.70 RC3Very LowLowObject for efficient automatic periodic pavementTracked on GitHub
0%
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.

245OtherFeature RequestAllDeferLowPOVMS message queue can fill up with GB of data for ver...Tracked on GitHub
0%
Future release Task Description

With very fast renders and very large output files, the message queue can fill up because the producers are not limited by IO, while the consumer performance is limited by disk IO. Consequently, the message queue can fill up to exhaust all available memory. The solution is to build in some better control of pending output data in the message queue on the producer side. This will also pave the way for message communication over slow links (i.e. a network).

248Parser/SDLFeature RequestNot applicableVery LowLowImplement mechanism to compute direction of a splineTracked on GitHub
0%
Future release Task Description

The SDL currently provides no way to compute the exact direction of a spline at a given location, even though mathematically this is a piece of cake: The first-order derivative of any spline section gives you the “speed” as a vector function, and is trivial to compute for polynomial splines (which are behind all spline types that POV-Ray supports); the normalized “speed” vector, in turn, gives the “pure” direction.

For exact direction/speed computations, I propose to extend the SDL invocation syntax as follows to allow for evaluating a spline’s derivative:

    SPLINE_INVOCATION:
        SPLINE_IDENTIFIER ( FLOAT [, SPLINE_TYPE] [, FLOAT] )

or

    SPLINE_INVOCATION:
        SPLINE_IDENTIFIER ( FLOAT [, FLOAT] [, SPLINE_TYPE] )

where the second FLOAT will specify the order of derivative to evaluate (defaulting to 0). In order to compute the position, direction, and acceleration of an object traveling along a certain spline, one could then for instance use:

    #declare S        = spline { ... }
    #declare Pos      = S(Time);
    #declare VSpeed   = S(Time,1);
    #declare VAccel   = S(Time,2);
    #declare Dir      = vnormalize(VSpeed);
    #declare Speed    = vlength(VSpeed);
    #declare AccelDir = vnormalize(VAccel);
    #declare GForce   = vlength(VAccel) / 9.81;

Alternatively, a mechanism may be devised to create a spline representing another spline’s derivative; however, it would be debatable whether the syntax should be parameter-like (being an added information that could be overridden again when creating other splines from such a derived spline), or operation-like (converting the spline), and in the latter case how it should affect spline type (and consequently control points); so the spline invocation parameter approach might be more straightforward, with less potential surprises for the user.

256Texture/Material/FinishFeature Request3.70 RC6Very LowLowCSG texturing modesTracked on GitHub
0%
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.

263Parser/SDLFeature Request3.70 RC6Very LowLowFunctions and patterns for finish variationsTracked on GitHub
0%
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.

281Geometric PrimitivesFeature Request3.70 RC7DeferLowBug in rendering of Bézier patchesTracked on GitHub
0%
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> }

}

282Image formatFeature RequestNot applicableDeferLowUnrendered region should be transparent, not blackTracked on GitHub
0%
Future release Task Description

When rendering only a region of a file, using the command-line options +sc/+sr/+ec/+er, the area of the image that is excluded comes out as black in the final PNG.

Expected behaviour is for it to be transparent.

299Parser/SDLFeature Request3.70 RC7Very LowLowObject Properties FeatureTracked on GitHub
0%
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

  • declare which properties a certain object can have
  • set these properties inside the object statement in which the object is used.

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.

310EditorFeature Request3.70 RC7Very LowLowEditor should remember bookmarksTracked on GitHub
0%
Task Description

Now the editor remembers only the cursor positions of the loaded files when starting a new PR session. It would be more friendly to remember whether the window was split or not, as well as the bookmarks.

319Texture/Material/FinishFeature Request3.70 releaseVery LowLowAdd interior to #default directiveTracked on GitHub
0%
Task Description

When working with predefined materials, it would be useful to have something like:

#if (!Use_photons)
  #default { interior { caustics 1 } }
#end

#include "my_predefined_materials.inc"

Default medias or IORs could also be useful.

327Parser/SDLFeature Request3.70 releaseVery LowLowSupport for non-ASCII characters in filename stringsTracked on GitHub
0%
Task Description

pov 3.7 Can not identify the Chinese.I give the texture map filename in chinese,it turns out parse error.

333User interfaceFeature Request3.70 releaseVery LowLowMake text in "about" alt+b dialog selectable with the m...Tracked on GitHub
0%
Task Description

When you press alt+b or access the “about” dialog in the Help menu it displays some text including software version number and list of contributors.

It would be nice to be able to select and copy this text using this mouse. Sometimes in the newsgroup I have to tell people what version of POVray I am using, and typing the version number can be a pain.

334Texture/Material/FinishFeature Request3.70 releaseVery LowLowHLS colorsTracked on GitHub
0%
Task Description

It would be nice to be able to specify colors in HLS as well as RGB.

Currently, you can use a macor to convert individual colors. But this does not work in color_maps where you want smooth gradations/interpolations between two or several colors.

25AnimationDefinite Bug3.70 beta 32DeferLowPause sometimes fails when rendering animationTracked on GitHub
90%
Task Description

There is an issue where the pause button in POVWIN will sometimes not work during an animation (primarily where the frame rate is high), and furthermore, POVWIN can then get into a state where it’s not possible to use the pause until it is re-started.

Newsgroup report.

26Geometric PrimitivesDefinite Bug3.61Very LowLowArtifacts rendering a cloth which has two-side texturesTracked on GitHub
0%
Future release Task Description

Dear PovRay maintainers and developers, congratulations for your great RayTracer!

We think that we have found a bug while we were rendering a piece of cloth.

In this piece of cloth were defined two textures, one for one side and one for the another side:

  texture { mesh_tex0_0 }
  interior_texture { mesh_tex0_1 }
  • Please: Look at line 77414 of the attached file “test.pov” to see

these definitions in their original context.

We have found some artifacts in the final rendering, in concrete near some wrinkles,
please, look at the attached file “render_artifacts.tga”, I have painted a big green arrow
near the artifacts, maybe you’ll need to do a zoom to see them more accurately.

They are as though the texture of the other side was painted in the incorrect side.

Fortunately, we have a patch to fix this bug (thanks to Denis Steinemann, he made the
implementation for PovRay 3.5, so I have adapted these changes to release 3.6.1)

Although we have found this bug in the Windows and Linux 3.6.1 releases,
the patch was generated in Linux (using the source code release of “povray-3.6.1”).

To apply this patch, inside the parent folder of the directory “povray-3.6.1” execute:

            patch -p0 < other_side_artifacts.patch

And the “povray-3.6.1” will be patched and you will get a console output like this:

 patching file povray-3.6.1/source/lighting.cpp
 patching file povray-3.6.1/source/mesh.cpp
 patching file povray-3.6.1/source/render.cpp

We don’t know if this “hack” is enough smart to apply in the next release,
but we think that it fixes the bug (the artifacts dissapear).

Best regards and thank you very much for your great RayTracer!

196Subsurface ScatteringDefinite Bug3.70 RC3Very LowLowMore SSLT CaveatsTracked on GitHub
90%
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.

202Geometric PrimitivesDefinite Bug3.70 RC3Very LowLowNumerical oddities in Julia_FractalTracked on GitHub
0%
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.

222Geometric PrimitivesDefinite Bug3.70 RC3Very LowLowincorrect render of CSG merge with radiosityTracked on GitHub
0%
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:

  1. 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)
  2. 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.

252PhotonsDefinite Bug3.70 RC6Very LowLowphotons and light_group is brokenTracked on GitHub
0%
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.

275Light sourceDefinite Bug3.70 RC7Very LowLowcircular area lights exhibit anisotropyTracked on GitHub
50%
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}
287Light sourceDefinite Bug3.70 RC7Very LowLowarea_illumination shadow calculationTracked on GitHub
50%
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

295User interfaceDefinite Bug3.70 RC7Very LowLowMinor GUI BugsTracked on GitHub
0%
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.

301OtherDefinite Bug3.70 RC7Very LowLowFallback to default image size causes wrong values to b...Tracked on GitHub
50%
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.)

309Parser/SDLDefinite Bug3.70 RC7Very LowLowWarning Message MissingTracked on GitHub
0%
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.

321OtherDefinite Bug3.70 releaseVery LowLowbounding threshold inconsistencyTracked on GitHub
90%
Task Description

User reported documentation inconsistency. Investigation led to the discovery of a bug in the setting of the current default value.

~source/frontend/renderfrontend.cpp reports the value “3” while ~source/backend/scene/scene.cpp sets a default value of “1”

Before for addressing this issue, are there any thoughts as to what the default value should be?

326OtherDefinite Bug3.70 releaseVery LowLowrestricted setting ignored in 3.7Tracked on GitHub
0%
Task Description

Due to a typo in the conf file parser (introduced, I think, in refactoring after 3.6), the restricted setting is ignored, and access checks aren’t performed.

Fixing this reveals some other issues:

  • %INSTALLDIR%/../../etc is incompletely canonicalized to /usr/local/share/../etc, not /usr/local/etc
  • read+write paths are added to the read list only, so writing is impossible

See attached patch.

Relatedly, I think it would be nice to add a new replacement token %CONFDIR% instead of %INSTALLDIR%/../../etc.

Also, there’s a realpath function that could simplify path handling, though I’m not sure if it’s available on all platforms.

99Refactoring/CleanupUnimp. Feature/TODO3.70 beta 36DeferVery LowRefactor engine (front- & back-end) code for Unicode su...Tracked on GitHub
0%
Future release Task Description

Front- & Back-end code should be refactored for full Unicode support in scene files and strings.

323User interfacePossible Bug3.70 releaseVery LowVery LowTooltip for render speed status bar has wrong unitTracked on GitHub
0%
Task Description

Tooltip popup for render speed always displays as “Pixels per Second” rather than matching status bar. I’ve noticed it in 3 renders so far. Most of my renders are fast enough not to see any other unit besides PPS, but I should be able to reproduce again if necessary.

20User interfaceFeature Request3.70 beta 32Very LowVery Lowrender window behaviorTracked on GitHub
0%
Task Description

When changing the behavior of the render window, “Keep above main”, requires restarting the POV editor to take effect. It would be nice either to get a warning to restart, or to get it to work without restarting.

86Parser/SDLFeature RequestNot applicableDeferVery LowAdd support for more RNG typesTracked on GitHub
0%
Future release Task Description

The current 32-bit linear congruential generator used as RNG in POV-Ray is sometimes quite limited for some purposes and in a few cases its poor quality shows up (as has been demonstrated more than once in the newsgroup). Thus it would be nice if POV-Ray offered additional, higher-quality random number generators, besides the current one (which should probably remain for backwards compatibility). These RNGs could include algorithms like the Mersenne Twister and the ISAAC RNG, both of which have very decent quality and have an enormous periods (while at the same time being very fast).

After a long discussion, the following syntax for specifying the RNG type and seed (which may be larger than 32 bits) has been suggested:

seed(<value>) | seed(<type>, <value> [, <values>])

For example:

#declare Seed1 = seed(123); // Use the current RNG, with seed 123
#declare Seed2 = seed(1, 123); // Identical to the previous one
#declare Seed3 = seed(2, 456, 789, 123); // Use RNG algorithm #2,
                                         // with a large seed (96 bits specified here)

A C++ implementation of the ISAAC RNG can be found at http://warp.povusers.org/IsaacRand.zip

87Geometric PrimitivesFeature RequestNot applicableDeferVery LowAdd new feature: Reference objectTracked on GitHub
0%
Future release Task Description

When you instantiate an object several times, eg:

object { MyObj translate -x*10 }
object { MyObj translate x*10 }

POV-Ray will copy that object in memory, at least for most types of objects. Not for all of them, though. Most famously if MyObj is a mesh, it won’t be copied, but only a reference to the original will be used, thus saving memory. (There are a few other primitives which also don’t cause a copy, such as bicubic_patch and blob, but those are naturally not so popular as mesh, so it’s a less known fact.)

AFAIK the reason why referencing (rather than copying) is not used for all types of objects is rather complicated, and mostly related to how transformations are applied to these objects. For example if the object being instantiated is a union, the translates above will be (AFAIK) applied to the individual members of the union rather than to the union object itself.

Copying, however, can be quite detrimental in some situations. For example if you have a huge union, and you want to instantiate it many times, the memory usage will be that many times larger (compared to just one instance). This is sometimes something which the user would not want, even if it made the rendering slightly slower as a consequence. (In other words, better to be able to render the scene in the first place, rather than running out of memory.)

Redesigning POV-Ray so that all objects would be referenced rather than copied would probably be a huge job, and in some cases a questionable one. There probably are situations where the current method really produces faster rendering times, so redesigning POV-Ray so that it would always reference instead of copy, could make some scenes render slower.

So this got me thinking about an alternative approach: How hard would it be to create a special object which sole purpose is to act as a reference to another object, without copying it? This special reference object would act as any regular object, would have its own transformation matrix and all that data related to objects, but its sole purpose is to simply be a “wrapper” which references an existing object. It could be, for example, like this:

object_ref { MyObj translate -x*10 }
object_ref { MyObj translate x*10 }

The end result would be exactly identical as earlier, but the difference is that now MyObj behaves in the same way as a mesh (in the sense that it’s not instantiated twice, but only once, even though it appears twice in the scene), regardless of what MyObj is.

In some cases this might render slightly slower than the first version (because POV-Ray has to apply the transformations of the object_ref first, after which it applies whatever transformations are inside MyObj), but that’s not the point here. The point is to save memory if MyObj is large.

An object_ref would behave like any other object, so you could do things like:

#declare MyObjRef = object_ref { MyObj };

object { MyObjRef translate -x*10 }
object { MyObjRef translate x*10 }

(The only thing being instantiated (and copied) here is the “MyObjRef” object, not the object it’s referring to, so that actual object is still stored in memory only once.)

In some situations it might even be so that referenced objects actually render faster than if the objects were copied because references increase data locality, lessening cache misses.

I believe this could be a rather useful feature and should be seriously considered, unless there are some major obstacles in implementing it.

129Parser/SDLFeature Request3.70 beta 37aDeferVery LowHash arraysTracked on GitHub
0%
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.

133Geometric PrimitivesFeature Request3.70 beta 37aDeferVery LowSubdivision supportTracked on GitHub
0%
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.

242OtherFeature RequestAllDeferVery LowAlgorithm to fix the so-called shadow line artifactTracked on GitHub
0%
Task Description

The so-called shadow line artifact (http://wiki.povray.org/content/Knowledgebase:The_Shadow_Line_Artifact) which affects objects with a ‘normal’ statement as well as smooth meshes and heightfields can be really annoying sometimes. Currently the only way to remove it is to make the object shadowless, which isn’t a good solution except in very special cases.

This algorithm could remove the artifact: If the actual normal vector of the object points away from the light source (its dot-product with the light vector is negative) but the perturbed normal points towards it (dot-product positive), then ignore the first shadow-test intersection with the object itself.

There are alternative ways of implementing an equivalent functionality:

- Don’t check the condition (if it’s too difficult to check due to how the code is designed) but always ignore the first intersection with the objects itself. This will work properly with closed surfaces but not with open ones, so it might need to be a feature for the user to turn on with a keyword (similar to eg. ‘double_illuminate’).

- Alternatively, don’t ignore the first intersection, but instead ignore the “opposite side” of the object’s surface (again, possibly only if a keyword has been specified). In other words, if we are rendering the outer side of the object, ignore its inner side when shadow-testing, and vice-versa.

- Perhaps simply add a feature to make surfaces one-sided (similarly to how they can be made so in OpenGL and similar scanline rendering systems). In other words, the inner side of a surface is completely ignored everywhere, making the object virtually invisible from the inside. The advantage of this feature would be that it can have uses other than simply removing the shadow line artifact.

272OtherFeature Request3.70 RC6DeferVery LowMinor change, significant speedup in cubic polynomial s...Tracked on GitHub
0%
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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