POV-Ray

As I posted yesterday to the POV bugreports, I observed a bug with the #write directive, having forgotten the closing bracket. I looked a little bit closer and found different behaviours of POV with different array sizes.

With ArrayDim=100 (please look at the attached SDL-code, which is reduced as much as possible and produces only the bug and no scene) one get the Parse Error: “Expected ‘string’, End of File found instead” and the last line is highlighted. With ArrayDim=1024 you get an Stack Overflow and POV crashes.

I observed this at two different core i7 windows machines. On one of them (16 GB RAM, if this is of importance) the threshold between both behaviours was between 300 and 400. Hope this helps.

Best regards,
Michael

From synthetic post of Cousin Ricky in p.beta-test, 2013-06-24 circa 3:19 pm (MST)

William F Pokorny anonymous@anonymous.org wrote:
> It seems to be the case the gradient warnings are only generated if the
> isosurface is naked. If it is wrapped in an object as was the case with
> my thread safety example, we get no warnings.

Confirmed. If only I still had the concentration required to investigate
computer code.

#version 3.7;

#ifndef (MG) #declare MG = 40/9; #end
#ifndef (Naked) #declare Naked = no; #end

global_settings
{ assumed_gamma 1
  radiosity {} //force isosurface calculations from all directions
}

light_source { <-3.3125, 7.6250, -5.7374>, rgb 1 }

camera
{ location <0.0000, 1.0000, -5.6713>
  look_at <-0.7969, 1.2000, -0.0598>
  angle 10.7447
}

#include "functions.inc"

#if (Naked)
  isosurface
  { function { f_sphere (x, 0, z, (2660 - 40*y) / 9) }
    contained_by { box { <-80, 31, -24>, <-128, 56, 24> } }
    max_gradient MG
    pigment { rgb <1, 0.75, 0> }
    scale 1/128
    rotate -35 * x
    translate y
  }
#else
  #declare Test = isosurface
  { function { f_sphere (x, 0, z, (2660 - 40*y) / 9) }
    contained_by { box { <-80, 31, -24>, <-128, 56, 24> } }
    max_gradient MG
    pigment { rgb <1, 0.75, 0> }
    scale 1/128
    rotate -35 * x
    translate y
  }
  object { Test }
#end

On the command line, try:

declare=MG=1 declare=Naked=1

and

declare=MG=1 declare=Naked=0

To lose the warning, I had to declare the isosurface. Just wrapping the naked
isosurface in an object{} generated a warning.

Further analysis

if((Stage == STAGE_SHUTDOWN) && (mginfo->refcnt == 0))

I’ve recently been working with the netpbm ppm format and I have hit what I believe to be a bug in the way ppm files are read – very likely a bug in all netpbm formats. I am aware of the long standing povray issue with the netpbm file formats header where the height and width need to be on the same line as the magic number though that is not a requirement of the official format. This bug is different.

Namely in working with a larger number of ppm files I hit cases where a few would fail with the message : “Possible Parse Error: Unexpected EOF in PPM file” though the ppm files are fine. What is happening is that the first byte of data after the line feed (LF) (Ubuntu linux 12.04) happens to have a carriage return (CR) value.

The code which is set up to interpret the netpbm headers is reading a lines with “file→getline (line, 1024);” and this line reading code is pulling in the first byte of data with the CR value as part of the line. When the read by binary data, 8 or 16 bits at a time, starts, the povray read code is offset into the data by one byte too many.

The result from 10,000 meters, if input values were completely random file to file, would be netpbm read fails for size that make no sense in 1/256 files. In practice & depending on data some might never see fails while an unfortunate few might almost always fail.

I’d make some argument any CR following a LF character should not be pulled in as part of the line read even on windows/dos systems where CRLF is the usual line termination order. I think though the real fix is better netpbm header reading code which more strictly breaks apart the header on the first whitespace character doing the last depth break, aware of the file size, so it can decide what portion of any valid sequence of whitespce characters after the decimal depth value is data and not whitespace.

The attached tarball when unpacked has both a passing and failing case. To run “povray fails.pov” or “povray works.pov”. The only difference between the two ppm files if the fails.ppm data is all 0x0D while works.ppm data bytes are all 0x0C. The image rendered is meaningless.

Thanks for your time.
Bill P.

The following paraboloid renders correctly:

intersection
{ quadric { <1, 0, 1>, <0, 0, 0>, <0, 1, 0>, -1 }
  cylinder { 0, y, 1 }
}

However, when I extend the clipping cylinder downward:

intersection
{ quadric { <1, 0, 1>, <0, 0, 0>, <0, 1, 0>, -1 }
  cylinder { -y, y, 1 }
}

the object disappears completely in POV-Ray 3.7 and 3.7.1. In POV-Ray
3.6.1, it renders as expected.

POV-Ray 3.7.0.unofficial (self-compiled with g++ 4.8, but completely unaltered)
POV-Ray 3.7.1-alpha.8150025.unofficial
openSUSE 13.2 GNU/Linux

This scene file illustrates the problem:

// +w480 +h240
#version 3.6; //[sic]

global_settings { assumed_gamma 1 }

camera
{ location <0, 1, -7.5958>
  look_at <0, 1, 0>
  right 2 * x
  up y
  angle 43.1038
}

#default { finish { diffuse 0.6 ambient rgb 0.15618 } }

light_source
{ <-4.3125, 9.6250, -7.4695>,
  rgb 6856.3
  fade_power 2 fade_distance 0.10417
  spotlight point_at <0, 1, 0> radius 45 falloff 90
}

box
{ -<9, 11, 9>, <9, 11, 9>
  pigment { rgb 1 }
}

plane
{ y, 0
  pigment { checker rgb 0.05 rgb 1 }
}

intersection
{ quadric { <1, 0, 1>, <0, 0, 0>, <0, 1, 0>, -1 }
  cylinder { 0, y, 1 }
  pigment { green 0.5 }
  translate <-1.25, 1, 0>
}

intersection
{ quadric { <1, 0, 1>, <0, 0, 0>, <0, 1, 0>, -1 }
  cylinder { -y, y, 1 }
  pigment { green 0.5 }
  translate <1.25, 1, 0>
}

On the right side, there should have been a cylinder capped with a paraboloid. A thread has been started in povray.bugreports. Jerome has started to look at it.

Reported in p.beta-test by James Dietrich (2013-12-12)

when the display window must be scaled (because one or both dimensions are larger than the actual screen), the ratio of scale might be too large in some occasion, performing a memory corruption in two places and usually crashing povray.

How to reproduce, with a 1920×1080 display (or 1920×1200):

povray +W2596 +H1003 +Ispiral.pov +Ospiral.png +D

In POV-ray 3.7 beta 33 under Windows XP, the editor’s MRU list incorrectly handles files that have a comma in the pathname. Only the part of the name before the comma appears on the MRU list, but the rest of the name is left off.
Consequently, the file cannot be reopened via the MRU list. The file is also not reopened on launch if pov was closed with the file open. This also occurs in 3.6.1, I haven’t tried it under 3.6.2 yet.

Interestingly enough, a quick peek in the registry shows that both 3.6 and 3.7
are saving the entire path name correctly under HKEY_CURRENT_USER\Software\POV-Ray\v3.6\POV-Edit\Recent (or \v3.7\POV-Edit\Recent).

This seems to be limited strictly to the editor’s MRU list. The file can still be opened normally using the open dialog box. Calling POV-ray from the command line and using a file or path name with commas in it works correctly. Included files with commas in the path work correctly, and the Tools→Edit last rendered file/View last rendered file work correctly also.

To duplicate, save a file with a comma in the pathname (either in the directory
name or the filename itself). Close the file, then attempt to reopen it using the MRU list in the file menu.

Windows allows you to associate programs with file extensions using the “Open with” file manager right-click menu extension.

I’m running Windows 7 64bit, and installed the 64 bit versions of 3.6.2 and the beta appropriately.

A couple of problems that I haven’t tested very thoroughly:

1. If you have both POV 3.6.2 and the beta installed at the same time, you can no longer using this dialog change the association to the beta once it has been created for 3.6.2. There’s no error or anything; it just opens the file inside 3.6.2 instead. Maybe because both versions appear as “POV-Ray for Windows” to this dialog? Would adding the version number to the name fix things? Anything I can do on my end of things to resolve this?

2. In POV-Ray 3.6.2, I can use this dialog to open *.inc, *.txt and other files in POV-Ray, but only if POV-Ray isn’t already running. If POV-Ray is already running I get an “Only /EDIT and /RENDER may be passed to previous instance” error. Files with the *.pov extension open properly regardless, without any error. I am unable to test this in the beta at the moment due to the first problem unfortunately. Could someone please test this with the beta and confirm whether the behavior also exists?

3. With the POV-Ray 3.7 beta, entering the following command in the command prompt results in the same error:

   "C:\Program Files\POV-Ray for Windows v3.7\bin\pvengine64.exe" "D:\Working\Povray\GearHead\LoadingScreen\btr_maanji.pov"

If I change it to the following it works however:

   "C:\Program Files\POV-Ray for Windows v3.7\bin\pvengine64.exe" /EDIT "D:\Working\Povray\GearHead\LoadingScreen\btr_maanji.pov"

Is this error/behavior really necessary? Would it be OK to instead change the behavior when the /EDIT flag is omitted in the
command-line such that the file is opened in the editor by default, without throwing an error?

I/O Restriction defaults are not being properly set on a fresh install of POVWIN.

See this thread for more information.

As posted in povray.beta-test 2012-01-14 with the same subject.

OS Win7 32 bit

The following code fails with the following message:
Picture index out of range.
Picture index out of range.
Fatal error in renderer: Uncategorized error.
Render failed

The texture scale is relevant.

It does not fail in Pov 3.62
The image map can be downloaded from:
http://www.mmedia.is/~bjj/data/s_rings/sat_ring_color.png

(Attached)

#version 3.7;

global_settings {
adc_bailout 0.0039
ambient_light rgb <1.000,1.000,1.000>
assumed_gamma 1.00
irid_wavelength rgb <0.250,0.180,0.140>
max_trace_level 5
number_of_waves 10
noise_generator 3
charset ascii
}

background { colour rgb <0.000,0.000,0.000> }

#declare Ring_Texture1 =
texture {
uv_mapping
pigment {

image_map{
 png "sat_ring_color.png"
 interpolate 2
 map_type 0
}
rotate    <90.000,90.000,0.000>

}

finish {

ambient     rgb <0.100,0.100,0.100>
brilliance  1.000
crand       0.000
diffuse     0.600
metallic    0.000
phong       0.000
phong_size  40.000
specular    0.000
roughness   0.050

}

}

#declare Camera0 =
camera {
perspective
location <3843.816,38.892,-2660.667>
up y
right 1.333*x
angle 33.000
sky ←0.004,1.000,0.002>
look_at < 0.449, 18.943, 0.102 >
} end Camera0 disc { Disc0
0,y,4.400000,2.500000
texture{ Ring_Texture1 }

  scale     <750.000000,750.000000,750.000000>      // Fails 32 bit

scale <800.000000,800.000000,800.000000> Fails 64 bit
scale <600.000000,600.000000,600.000000> does not fail
rotate <0.000000,0.000000,-20.000000>
translate ←3500.000000,900.000000,900.000000>
} end Disc0 camera{ Camera0 } ///

The +GD flag gives me an “Invalid parameter” error, whether on the command line or in a .ini file.

Debug_File= still works.

I reported this in povray.beta-test, but did not receive a response.

The problem occurs in both Windows 7 and in Linux.

Consider the following script:

  #fopen F "foo.txt" read
  #read (F, Foo)
  #debug concat ("'", Foo, "'\n")
  #fclose F

Now assume that foo.txt erroneously contains unquoted text (which will result in a parse error):

  Blah

When the error is reported, POV-Ray for Windows will helpfully open foo.txt, but any attempt to save a corrected version of foo.txt will fail until you exit the POV-Ray GUI, presumably because foo.txt is not properly closed by the parser.

I reinstall a system, (so ~/.povray was not existant), and then
installed povray from sources, as a normal user (excepted the
installation step):

$ ./configure ...
$ make
$ make check
$ sudo make install

I find these steps pretty much standard.

The problem I’m noticing is that the $HOME/.povray hierarchy get owned
by root (hey, it’s *MY* directory !). There is a chown in the Makefile
for the target files (povray.ini & povray.conf), as well as subtree but:

* povowner & povgroup are hard coded to 0 (I would expect a copy of the
owner & group of $HOME, wouldn’t I ?)

For getting povowner, I would suggest `stat -c “%u” $HOME`
For povgroup, `stat -c “%g” $HOME`

Are they portable enough ? (I could ask on Monday a Solaris system, but
I do not have bsd and the other flavours of unix)

(Stat is in section 1 of man, part of gnu coreutils, /usr/bin/stat)

Side note: This is fine to install for the local user, but new later
users could benefit also from a ~/.povray/3.7/ subtree ; what about also
filling the /etc/skel (when available) ? (and in /etc/skel, root owner
is fine!)

POV-Ray fails to accept UTF-8 encoded files with a leading Byte Order Mark.

According to the code it was intended to recognize a leading BOM (or, more precisely, leading non-ASCII code sequences) and automatically switch to UTF-8, so this must be considered a bug rather than a missing feature.

Quoted strings as parameters to command-line options work on the command line but not in INI files; e.g.:

+i"test.pov"

Root cause has already been identified (actually the problem was found during code inspection) and a fix is under way.

When running make on Linux, the backend source files (and possibly others?) are apparently compiled twice: first from the .../source/backend/ directory, and another time from the .../source/ directory. As an example, here are the corresponding lines for sphsweep.cpp:

g++ -DHAVE_CONFIG_H -I. -I../.. -I../.. -I../../source -I../../source -I../../source/base -I../../unix -I../../vfe 
-I../../vfe/unix -pthread -I/usr/include/OpenEXR    -pthread -I/usr/include  -pipe -Wno-multichar -Wno-write-strin
gs -fno-enforce-eh-specs -s -O3 -ffast-math -pthread -MT sphsweep.o -MD -MP -MF .deps/sphsweep.Tpo -c -o sphsweep.
o `test -f 'shape/sphsweep.cpp' || echo './'`shape/sphsweep.cpp

g++ -DHAVE_CONFIG_H -I. -I..  -I.. -I../source/backend -I../source/base -I../source/frontend -I../unix -I../vfe -I.
./vfe/unix -pthread -I/usr/include/OpenEXR    -pthread -I/usr/include  -pipe -Wno-multichar -Wno-write-strings -fno
-enforce-eh-specs -s -O3 -ffast-math -pthread -MT sphsweep.o -MD -MP -MF .deps/sphsweep.Tpo -c -o sphsweep.o `test 
-f 'backend/shape/sphsweep.cpp' || echo './'`backend/shape/sphsweep.cpp

This is especially annoying on platforms that are rather slow at compiling.

The following scene has four spheres with different pigment color & filter settings:

- Left: filter 1
- Right: filter 0

- Top: red 0.0 green 0.5 blue 1.0
- Bottom: red 0.00 green 0.05 blue 0.10 (10% of the above)

Background is set to black, so that we only see the diffuse component of the object’s effective color.

Theoretically, both left spheres should be invisible, as they are fully transmissive (with a filtering effect), but apparently with a high filter setting, reducing an object’s pigment color actually increases the object’s effective diffuse color.

//+w600 +h600

global_settings{ assumed_gamma 1.0 }

camera {
  orthographic
  location  <0,0,-10>
  right 4*x
  up 4*y
  look_at   <0,0,0>
}

light_source{<10,10,-10> color rgb 1 parallel }

background { color rgb 0 }

default {
  finish {
    ambient 0
    diffuse 1
    specular 0
    phong 0
    reflection { 0.0 }
  }
}


sphere { <-1, 1, 0>, 0.8 texture { pigment { color rgb <0,0.5,1.0> filter 1.0 } } }
sphere { < 1, 1, 0>, 0.8 texture { pigment { color rgb <0,0.5,1.0> filter 0.0 } } }

sphere { <-1,-1, 0>, 0.8 texture { pigment { color rgb <0,0.5,1.0>*0.1 filter 1.0 } } }
sphere { < 1,-1, 0>, 0.8 texture { pigment { color rgb <0,0.5,1.0>*0.1 filter 0.0 } } }

This bug has been around in 3.6 already.

When using fade_distance and fade_power in combination with area_illumination, the light source fading is not applied to materials with subsurface scattering; see the following code for an example:

#version 3.7;
global_settings {
  assumed_gamma 1.0
  mm_per_unit 10
  subsurface { samples 200,20 }
}

camera {
  right x*image_width/image_height
  angle 30
  location  <0,1.5,-4>
  look_at   <0,0,0>
}

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 {
      checker
      color rgb <1.0, 0.8, 0.6>
      color rgb <1.0, 0.0, 0.0>
      scale 0.5
    }
  }
}

light_source {
  <50,50,50>
  color rgb 30
  area_light 5*x,5*y,17,17 adaptive 1 jitter circular orient
  area_illumination on
  fade_distance 10
  fade_power 2
}

cylinder {
  <0,0,0>, <0,0.2,0> 1
  texture {
    pigment { color rgb 1 }
    finish {
      ambient 0
      diffuse 0.7
      specular albedo 0.3
      reflection { 0.3 fresnel }
      conserve_energy
      subsurface { translucency 0.1 }
    }
  }
  interior { ior 1.5 }
}

sphere {
  <0,0.4,0>, 0.2
  texture {
    pigment { color rgb <1,0.6,0.0> }
    finish {
      ambient 0
      diffuse 0.0
      specular albedo 0.8 metallic
      reflection { 1.0 metallic }
      conserve_energy
    }
  }
}

Thread safety issue in functions using splines. 3.7.0.RC7.

First vetting in p.bugreports where several users were able to reproduce the fail on the following systems:

1) Ubuntu 12.1 i7 920 using 3.7.0.RC7
2) Ubuntu 12.04, AMD 2431 CPU, Linux 3.2.0-45 kernel using 3.7.0.RC7 (g++ 4.6 @x86_64-unknown-linux-gnu)
3) POV-Ray 3.7.0.RC7 (icpc 13.1.0 @x86_64-unknown-linux-gnu)

 Intel(R) Xeon(R) CPU E5-2680 0 @ 2.70GHz

 uname -or
 2.6.32-279.14.1.el6.x86_64 GNU/Linux

 lsb_release -irc
 Distributor ID: CentOS
 Release:        6.3
 Codename:       Final

4) Confirmed with openSUSE 12.2.
5) Just to add to the system list: with Windows and a core i7 one yields the same result.
6) “Le_Forgeron” ran under Intel Inspector (XE 2013) and provided this feedback :

 ...
  that might be less than 60 seconds, but with Intel Inspector (XE 2013),
 it becomes 42:50 (just 14 data races, oh well, that's just so friendly).

 ID  Type Sources Modules State
 P1  Data race isosurf.cpp; mutex.hpp povray New
 P2  Data race mutex.hpp; povms.cpp povray New
 P3  Data race povray.cpp povray New
 P4  Data race povray.cpp povray New
 P5  Data race mutex.hpp; pov_mem.cpp; splines.cpp povray New
 P6  Data race mutex.hpp; pov_mem.cpp; splines.cpp povray New
 P7  Data race mutex.hpp; pov_mem.cpp; splines.cpp povray New
 P8  Data race recursive_mutex.hpp; scene.cpp; task.cpp; taskqueue.cpp;
 view.cpp povray New
 P9  Data race condition_variable.hpp; vfe.cpp; vfesession.cpp povray New
 P10  Data race condition_variable.hpp; unixconsole.cpp; vfesession.cpp
 povray New
 P11  Data race condition_variable.hpp; unixconsole.cpp; vfesession.cpp
 povray New
 P12  Data race unixconsole.cpp; vfesession.cpp; vfesession.h povray New
 P13  Data race unixconsole.cpp; vfesession.cpp povray New
 P14  Data race [Unknown]; unixconsole.cpp; vfesession.cpp
 libboost_thread.so.1.49.0; povray New

 Numbers 2, 3, 4, 8, 9, 10, 11, 12, 13 & 14 are related to the handling
 of session (and occur once or twice only, excepted #8, four times).

 Number 1 is about isosurface (adjusting gradient at isosurf.cpp:1099 vs
 1098 (testing its value), and copying the isosurface) (IMHO, rendering
 threads updating the object... not the best move without some
 atomic/protection (and not sure a DBL is/can be atomic)) (occurs 2505
 times).

 Number 5, 6 and 7 are about splines
 * sp->Cache_Type & Cache_Point, splines.cpp :803 vs :814/815 (2024 times)
 * sp->Cache_Valid, :805 vs :813 vs :904 (1770 times)
 * sp->Cache_Data, :807 vs :903 (5025 times)

 Only my 0.02¢ (yes, very cheap), but it seems to confirm

For test code see attached files or SplineThreadSafety.pov attachment to
p.bugreports and images were posted to p.b.images.

Issue shows up any time more than one thread is used. Use of AA tends to hide
the problem so do not use it if using the output image for testing.

Thanks.
Bill P.

Using an end value of 1048576 or larger in a #for loop will cause the last iteration to be skipped, as can be demonstrated by the following code:

#declare N = 2000000;
#debug concat(”N = “,str(N, 0,50),”\n”)
#debug concat(”N-5 = “,str(N-5,0,50),”\n\n”)
#for (I, N-5, N, 1)

#debug concat("I   = ",str(I,0,50),"\n")

#end

(The limit was observed with a Win64 build; other builds may exhibit other limits or might even work fine, depending on the floating point engine used.)

As this limit is still far below the numeric precision limit, and a corresponding #while loop works fine with much higher values, this must be considered a bug rather than an inevitable limitation.

The bug can be tracked down to a faulty condition in tokenize.cpp, Parser::Parse_Directive(), CASE(END_TOKEN), case FOR_COND:

    if ( ((Step > 0) && (*CurrentPtr >= End + EPSILON)) ||
         ((Step < 0) && (*CurrentPtr <= End - EPSILON)) )

which should instead be:

    if ( ((Step > 0) && (*CurrentPtr > End + EPSILON)) ||
         ((Step < 0) && (*CurrentPtr < End - EPSILON)) )

Due to a recent thread in povray.general (7th September 2013), I dive
into the code of height field creation.

There is 2 TODO in source/backend/support/imageutil.cpp, for
image_height_at() (circa line 512)

The first one is about using the index of palette-image: As far as *257
would indeed perform a better job to cover the full range than *256, it
would break backward compatibility with previous versions of povray (3.6
included) which only promoted the index as the Most significant byte,
keeping the least one at 0.

But on the second one, the new formula is plain wrong: (r*255+g)*255
should be (r*256+g)*255.
In previous versions, r*255 was the Most significant byte, and g*255 was
the least one.
Ergo, the value was r*255*256 + g*255, which can and should be only
factored as (r*256+g)*255;

I know it is damn late in the release schedule, but can that be either
be fixed before final official delivery or a memo added to the release
note that it would be fixed later and backward-bug will not be
maintained for that specific point (using rgb-8 or less bit per
channel-image for height field)

(it was not bugged in 3.6.1 nor before, it’s just that tiny little bit
of 3.7 that would should that bug)

If you look carefully at the attached pictures (povray +I... +H700 +W700 +A0.01) of scene and scene36, there is a significant difference at the top.
With 3.6, it matched exactly (hence the noise on the top pixels row) the view.
With 3.7, it cannot reach the top and leave a white area
(another difference is the slope on the side are also a bit more lower with 3.7, easier to spot when alternating the display of both pictures)

If you want to regenerate hf.png, it was rendered with povray 3.7RC7, +W400 +H400 +A0.01 +Ihf.pov

The white line at the bottom is expected, as the minimal value of the height field is “full green”

As the following scene demonstrates, the “inverse” keyword produces unexpected results with quadrics.

Left: a sphere primitive as reference
Right: a sphere-shaped quadric primitive (sphere-shaped)

Top: plain
Bottom: inverse

The objects are clipped in half to better demonstrate the effect. Regular texture is shown in white, interior_texture in red; the surface normal of a selected point (blue) as returned by trace() is shown in green.

Note how the sphere’s surface normal, as well as the textures, are flipped when “inverse” is used (this is the intended standard behaviour of all objects), while the quadric’s normal and textures erroneously remain uchanged.

// +w800 +h600

#version 3.7;

global_settings{ assumed_gamma 1.0 }

#default{ finish { ambient 0.1 diffuse 0.9 specular 0.5 }} 

camera {
  perspective
  angle 40
  right     x*image_width/image_height
  location  <0,0,-10>
  look_at   <0,0,0>
}

light_source{ < 1000,3000,-3000> color rgb 1 }

background { color rgb 0.5 }

#declare T_White = texture { pigment { color rgb   1 } }
#declare T_Red   = texture { pigment { color red   1 } }
#declare T_Green = texture { pigment { color green 1 } }
#declare T_Blue  = texture { pigment { color blue  1 } }

#declare TopLeft     = sphere { 0, 1 }
#declare BottomLeft  = sphere { 0, 1 inverse }

#declare TopRight    = quadric { <1,1,1>, <0,0,0>, <0,0,0>, -1 }
#declare BottomRight = quadric { <1,1,1>, <0,0,0>, <0,0,0>, -1 inverse }

#macro Mac(Obj, P, D)
  union {
    #local N = <0,0,0>;
    #local O = <-0.6,0.4,-10>;
    #local Q = trace(Obj, O, D, N);
    #if (vlength(N) > 0)
      sphere { Q, 0.05 texture { T_Blue } }
      cylinder { Q, Q + N, 0.02 texture { T_Green } }
    #else
      cylinder { O, O + D*10000, 0.02 texture { T_Red } }
    #end
    object { Obj texture { T_White } interior_texture { T_Red } clipped_by { box { <-1,-1,-1>, <0,1,1> rotate y*30 } } }
    translate P
  }
#end

Mac(TopLeft,     <-1.2, 1.2, 0>, z)
Mac(TopRight,    < 1.2, 1.2, 0>, z)
Mac(BottomLeft,  <-1.2,-1.2, 0>, z)
Mac(BottomRight, < 1.2,-1.2, 0>, z)

As the following scene demonstrates, the “inverse” keyword produces unexpected results with fractals.

Left: a sphere primitive as reference
Right: a julia fractal

Top: plain
Bottom: inverse

The objects are clipped in half to better demonstrate the effect. Regular texture is shown in white, interior_texture in red; the surface normal of a selected point (blue) as returned by trace() is shown in green.

Note how the sphere’s surface normal, as well as the textures, are flipped when “inverse” is used (this is the intended standard behaviour of all objects), while the fractal’s normal and textures erroneously remain uchanged.

// +w800 +h600

#version 3.7;

global_settings{ assumed_gamma 1.0 }

#default{ finish { ambient 0.1 diffuse 0.9 specular 0.5 }} 

camera {
  perspective
  angle 40
  right     x*image_width/image_height
  location  <0,0,-10>
  look_at   <0,0,0>
}

light_source{ < 1000,3000,-3000> color rgb 1 }

background { color rgb 0.5 }

#declare T_White = texture { pigment { color rgb   1 } }
#declare T_Red   = texture { pigment { color red   1 } }
#declare T_Green = texture { pigment { color green 1 } }
#declare T_Blue  = texture { pigment { color blue  1 } }

#declare TopLeft     = sphere { 0, 1 }
#declare BottomLeft  = object { TopLeft inverse }

#declare TopRight    = julia_fractal{ <-0.083,0.0,-0.83,-0.025> quaternion sqr max_iteration 8 precision 20 scale 0.9 }
#declare BottomRight = object { TopRight inverse }

#macro Mac(Obj, P, D)
  union {
    #local N = <0,0,0>;
    #local O = <-0.6,0.4,-10>;
    #local Q = trace(Obj, O, D, N);
    #if (vlength(N) > 0)
      sphere { Q, 0.05 texture { T_Blue } }
      cylinder { Q, Q + N, 0.02 texture { T_Green } }
    #else
      cylinder { O, O + D*10000, 0.02 texture { T_Red } }
    #end
    object { Obj texture { T_White } interior_texture { T_Red } clipped_by { box { <-2,-2,-2>, <0,2,2> rotate y*30 } } }
    translate P
  }
#end

Mac(TopLeft,     <-1.2, 1.2, 0>, z)
Mac(TopRight,    < 1.2, 1.2, 0>, z)
Mac(BottomLeft,  <-1.2,-1.2, 0>, z)
Mac(BottomRight, < 1.2,-1.2, 0>, z)

The following scene demonstrates how media sampling method 3 gives inaccurate results with scattering media.

The scene shows four spheres with uniform media, using (left to right) sampling methods 1, 2 and 3 with default settings, and sampling method 3 with high minimum sample count, respectively.

Note how changing the sample count significantly affects the result, despite the media being uniform.

Code analysis shows that the root cause is an underestimation of the extinction effect on the light scattered by the media, corresponding in order of magnitude to half the distance between mandatory samples (as defined by minimum sample count).

The effect also leads to visible artifacts when nesting hollow objects inside the media, as can be demonstrated by un-commenting the four smaller spheres.

#version 3.7;

camera {
  perspective angle 25
  location  <0.0 , 0.0 ,-20.0>
  right     x*image_width/image_height
  look_at   <0.0 , 0.0 , 0.0>
}

light_source {
  <0,3000,-3000> color rgb 1
}

background { color rgb 0.5 }

plane {
  <0,1,0>, -1
  texture { pigment { checker color rgb<1,1,1>*1.2 color rgb<0.25,0.15,0.1>*0 } }
}

#declare T_Transparent = texture {
  pigment { color rgbt <1,1,1,1> } finish { diffuse 1 }
}

sphere { <-3,0,0>, 1.00 
  texture { T_Transparent }
  hollow
  interior {
    media {
      scattering { 1 color rgb 2 extinction 1 }
      method 1
    }
  }
}

sphere { <-1,0,0>, 1.00 
  texture { T_Transparent }
  hollow
  interior {
    media {
      scattering { 1 color rgb 2 extinction 1 }
      method 2
    }
  }
}

sphere { <1,0,0>, 1.00 
  texture { T_Transparent }
  hollow
  interior {
    media {
      scattering { 1 color rgb 2 extinction 1 }
      method 3
    }
  }
}

sphere { <3,0,0>, 1.00 
  texture { T_Transparent }
  hollow
  interior {
    media {
      scattering { 1 color rgb 2 extinction 1 }
      method 3
      samples 100
    }
  }
}

/*
sphere { <-3,0,0>,0.8 texture { T_Transparent } hollow }
sphere { <-1,0,0>,0.8 texture { T_Transparent } hollow }
sphere { < 1,0,0>,0.8 texture { T_Transparent } hollow }
sphere { < 3,0,0>,0.8 texture { T_Transparent } hollow }
*/

#fopen directive w/o OPEN_TYPE (yeah, I forgot it, some other languages have ‘read’ as default value)

expected behavior:
Parse error msg “line XXX, OPEN_TYPE missing in #fopen directive”, then stop.

observed behavior:
crash - Segfault err (core dump) in Parsing stage

minimal working example attached

Adjusting the brightness of an image-mapped sky sphere, although not an uncommon task especially when using HDR light probes, currently is cumbersome at best, as it is not possible to specify a “finish { ambient ... }” statement.

To simplify tuning a sky sphere’s brightness, I suggest introducing a “brightness FLOAT” modifier (defaulting to 1.0) to either the sky_sphere block or (as a more versatile solution) the image_map statement.

Input image files may have been created with gamma pre-correction for some specific target gamma, which may vary from image to image. Some file formats like PNG or HDR support embedding gamma pre-correction information in the image file, but this information may be missing or faulty, and some formats don’t support it at all. Additionally, it may be desirable to tamper with an input image’s gamma for artistic reasons.

Therefore, I suggest adding a means to explicitly specify input images’ originally intended target gamma on a per-image basis, like:

image_map { jpeg "MyImage.jpg" assumed_gamma 1.8 }

Using a facet pattern in a normal map results in a unspecified error in Evaluate_TPat at the render stage.
This probably should be caught at parse time to give a more descriptive error and a line number.

Example:

sphere {
  0, 1
  texture{
    pigment{rgb <1,1,1>}   
    normal {
      facets
      normal_map {
         [0 bumps ]
         [0.5 facets ]
         [1 bumps ]
      }
    } 
  }
}

Adding an AOI pattern is asked for fairly frequently.

Linux beta 32, 64bits, compiled from sources.

povray -w800 -h600 +a0.3 +kfi1 +kff78
-L/usr/local/share/povray-3.7/scenes/incdemo
-Ii_internal.pov +WT5 +R4 +AM1 +MB1

Important issue: +WT5 +MB1

Seems Fine for +WT1 +MB1
Also fine for +WT5 +MB9

The intersection with the containing box displays some two-shades of grey
random checkered patterns.
Size of square looks like size of renderering thread. Position too.

Impacted frames (of 78):
01, 02, 03, 30, 48, 74, 76.

Function use in image maps is broken.

The following should result in a white and green checkered unit square, but is transparent.

camera {
   location  <0.0, 0.5, -4.0>
   direction 1.5*z
   right     x*image_width/image_height
   look_at   <0.0, 0.0,  0.0>
}

background {rgb <1,1,1>}

light_source {
  <-30, 10, -30>           
  color rgb <1, 1, 1> 
}

plane {y,-1 pigment{checker rgb <1,0,0> rgb <1,0.5,0.5> }}

plane {y,-0.99 
 pigment {
  image_map { 
   function 10,10 { 
    pigment {checker rgb <0,1,0>, rgb <1,1,1> scale 0.1}
   }
   once 
  }
  rotate <90,0,0>
 }
}

The parser is failing to read the .tiff file extension from the input string...

bump_map { tiff "earth03_hf2.tiff" }

Results in file not found, but

bump_map { tiff "earth03_hf2" }

will find the file. It might be that it’s not a three character extension?

I’ve been trying to upgrade povray 3.6.1 to 3.7-beta-32. I’ve configured with no additional arguments, and the configure dies with:

checking whether to build the boost thread library from sources... no
checking for boostlib >= 1.35... yes
checking whether the Boost::Thread library is available... yes
checking for exit in -lboost_thread... no
checking for exit in -lboost_thread-boost_thread... no
configure: error: Could not link against boost_thread-boost_thread !

I figured that the problem was with my boost installation (1.35) and upgraded boost to 1.39; the problem remains. I tried to see if exit was defined in libboost_thread and/or libboost_thread-boost_thread and it isn’t. Just to be sure that my currrent setup works for the released version, I rebuilt/reninstalled 3.6.1, which went without problem.

I’m on a slackware-12.2 box, using gcc-4.4.0.

After a recent update on the POV-Wiki the GuMax skin doesn’t recognize MediaWiki:Common.css entries.

The following files were garbled in changelist #4648 by stripping all line terminators, making the files unusable:

• .../scenes/advanced/cats/cattext.inc
• .../scenes/animations/life/blink4.inc
• .../scenes/animations/life/walker.inc

Line terminators of these files were already problematic in previous versions of the file, having been CR-only.

The following files changed with #4648 should be reviewed closely as well, as they were previously CR-only, too, and at least some of them exhibit some peculiarities regarding line and/or file terminators:

• .../scenes/animations/pentmap/pentmap.ini
• .../scenes/animations/pentmap/pentmap.pov
• .../scenes/animations/slinky/slnk.ini
• .../scenes/incdemo/metals/metals.doc
• .../scenes/incdemo/stones/stones.doc
• .../scenes/incdemo/woods/morewood.doc
• .../scenes/incdemo/woods/woods.doc
• .../scenes/textures/pigments/skies/skies.doc

Reported for freebsd 7.2 (current production version, true for previous version, unknown for 8.0 in beta now)

freebsd does not provide CLOCK_PROCESS_CPUTIME_ID
(even if CLOCK... is posix).

As a consequence, compilation of the unix-source is currently not possible for freebsd target.

Might be a simple selection for Change 4356 ?
(assuming a relevant test in ./configure)
(getrusage() seems available on freebsd, but does it provide the pieces of information needed, I do not know that code good enough to assert that)

It seems that the new area_illuminate flag for area lights does not take into account fade_power and fade_distance. The illumination falloff is still being calculated from the center of the light_source.

Here’s some relevant code:

camera{
  location<0,10,-10>
  look_at 0
}
plane{y,0 pigment{rgb 1}}
light_source{
  y*.1,100
  area_light x*10, z*1, 8, 8
  jitter
  area_illumination
  fade_power 2 fade_distance 1
}

When rendering a series of scenes (e.g. animation, or render queue in POV-Ray for Windows), number_of_waves is not properly reset to its default value between scenes, causing the parameter to default to the value set by the previous scene.

For instance, rendering the following scenes from a queue will cause “arches.pov” to be rendered differently the second time:

1. scenes\textures\finishes\arches.pov
2. scenes\textures\normals\normavg.pov
3. scenes\textures\finishes\arches.pov (again!)

The following (bogus) SDL code causes POV-Ray 3.7 beta to crash hard with an access violation:

#include "fubar.inc"
Bar(42)
#macro FooBar() #end

//fubar.inc
#macro Foo(Fnord) #end
#macro Bar(Ignord) Foo(23 #end

The parser does not accept mesh objects (or CSG objects including a mesh object) as a parameter to the inside() built-in function, reporting error “Solid object identifier expected”, even if the mesh is “solidified” by specifying an inside_vector.

(see news://news.povray.org:119/4a983716@news.povray.org)

It appears that reflective bounces from blobs are
not incrementing the trace level, causing self-
reflecting hall of mirror portions to stall renders.

I have installed POV-Ray 3.7 beta 34 on Windows 7
The setting ‘Output_Alpha=on’ doesn’t work as documented. With this setting the Background appear black and the scene is transparent.

Check with this Code:

camera {
   location  <3, 3, -3>
   direction <0, 0, 2.9>
   look_at   <0, 0, 0>
   right 1.0*x
}
light_source { < 3, 3, -3> color red 1 green 1 blue 1 }
sphere 
{
   <0,0,0> 0.8
   pigment {color rgb<1,1,0>}
   finish
   {
      ambient 0.2
      diffuse 0.8
   }
}

and with this ini file:

Input_File_Name=C:\Users\dfv_rei1\AppData\Local\Temp\Cuadrigula\PreviewObject.pov
Output_File_Name=C:\Users\dfv_rei1\AppData\Local\Temp\Cuadrigula\PreviewObject.tga
Output_File_Type=t
Output_Alpha=on
Bits_Per_Color=24
+W121 +H121
+a0.3
+q11
+a

(This happens as of beta 34)

The following scene will cause POV-Ray to allocate memory until all available memory is used, resulting in an Out of Memory error message:

#declare n1 = normal
{
    crackle .5
    scale 0.001
    accuracy 0.0001
}

#declare n2 = normal
{
    bumps 0
}

camera
{
    location <0, 0.2, -1>
    look_at <0.4, 0.3, 1>

    focal_point <0.4, 0.3-.0, 1>
    blur_samples 25
    confidence .9
    variance 0
    aperture .05
}

light_source
{
    <-10, 10,-5>, rgb 1.5
    area_light x*2,y*2,7,7 orient adaptive 2
}

sphere{ <0, 0, 0>, 0.5 pigment {color rgbf <0.85,1,.95,1>}

    interior
    {
        ior 1.5
        fade_color rgb <0.0, 0.5, 0.0>
        fade_power 2
        fade_distance 10.5
        dispersion 1.1
        dispersion_samples 100
    }

    normal {

        checker normal{n2} normal{n1}
        scale 0.1
        warp { spherical }

    }

    translate z*1
} 

The attached TIFF file was created with IC using compression. When used in an image_map, POV-Ray 3.7.0.beta.34 on Windows XP x64 renders the image all transparent, while POV-Ray 3.6.2 renders the file fine. The same effect can be seen with LZW-compressed TIFF files created with Adobe Photoshop 6.0.

Uncompressed TIFF files created with either IC or Photoshop render fine in both versions of POV-Ray.

Stepping through the code of POV-Ray 3.7.0 shows that the same code path is taken regardless of compression, but the libtiff library returns different alpha channel values, indicating a problem in that library. POV-Ray 3.7 still uses libtiff 3.6.1, whereas the POV-Ray 3.6 branch has been updated to libtiff 3.8.2, which according to the change history includes a few alpha-related changes.

Source code inspection during examination of issues with the scene published at http://povray.sitewww.ch/?p=177 show the following issues with current (beta.34) implementation of dispersion in POV-Ray 3.7:

• The same adjustment to the IOR that is applied at the very first dispersion interface is erroneously applied to all subsequent interfaces.

• As an exception, dispersion adjustment is erroneously not applied to any interface defined by the surface of a non-dispersing object embedded into a dispersing object.

While this still allows to use dispersion for artistic effect, it is neither physically realistic, nor does it match 3.6 behavior.

Add metatags to output images identifying the file as having been created using POV-Ray.

In the following scene, the mesh object will always cast a fully-opaque shadow, even if the image has an alpha channel:

camera {
  location  <0.5, 1.0, -1.0>
  look_at   <0.5, 0.0,  0.5>
}

light_source { <0, 30, 0> color rgb 1 }

mesh {
    triangle { <0,0,0>, <1,0,0>, <1,0,1> uv_vectors <0,0>, <1,0>, <1,1> }
    triangle { <0,0,0>, <1,0,1>, <0,0,1> uv_vectors <0,0>, <1,1>, <0,1> }
    texture { pigment { uv_mapping image_map {png "FOOBAR.png"} } }
}

plane { y, -0.1 pigment { color rgb 1 } }

The following modification to the texture will give the expected results:

    texture { uv_mapping pigment { image_map {png "FOOBAR.png"} } }

The problem can be observed with both POV-Ray 3.7 (tested with beta.34), as well as 3.6 (tested with 3.6.2).

Cone is not on good place when first base point is lower then end cap point.
Example:

cone { <0, 0, 0>, 2, <0, 1, 0>, 1 } - good
cone { <0, 0, 0>, 1, <0, 1, 0>, 2 } - bad

This is on 3.7 beta 35 version.

Hi,

following scene will not be rendered correctly in 3.7.beta.35a:

http://lib.povray.org/collection/beamtest/cousin%20ricky%201.1/beamtest.html

maybe it is a configuration problem or it is a real bug.

In pvengine.cpp (file revision 154), lines 4003-4006 are exact duplicates of lines 3999-4002:

3997    case KEYWORD_LOOKUP_MESSAGE :
3998         hh_aklink.pszKeywords = (LPCSTR) lParam ;

3999         if (strncmp (hh_aklink.pszKeywords, "oooo", 4) == 0)
4000           hh_aklink.pszKeywords = ""  ;
4001         if (strncmp (hh_aklink.pszKeywords, "//", 2) == 0)
4002           hh_aklink.pszKeywords = ""  ;

4003         if (strncmp (hh_aklink.pszKeywords, "oooo", 4) == 0)
4004           hh_aklink.pszKeywords = ""  ;
4005         if (strncmp (hh_aklink.pszKeywords, "//", 2) == 0)
4006           hh_aklink.pszKeywords = ""  ;

4007         HtmlHelp (NULL, engineHelpPath, HH_KEYWORD_LOOKUP, (DWORD_PTR) &hh_aklink) ;
4008         return (true) ;

This duplication appears pretty much useless to me - or am I missing something?

Many people clearly miss a simple for-loop construct in povray. It is indeed true that probably at least 99% of #while loops out there have the form of a simple for-loop. It’s much rarer to have to use more exotic forms of looping supported by the #while mechanism. Thus it would make sense if a #for construct would be added which would make writing such loops much easier and convenient.

The only remaining question would be the syntax.

IMO the for-loop construct should implicitly declare a local variable of a specified name, automatically increment it during the loop, and then undefine it after the loop ends. It could perhaps be something along the lines of:

#for(<identifier name>, <initial value>, <final value> [, <step>])
  <loop body>
#end

Example:

#for(Counter, 1, 10) // 'Counter' gets values 1, 2, 3, ..., 10
  #debug concat(str(Counter, 0, 0), "\n")
#end
#for(Counter, 1, 10, 3) // 'Counter' gets values 1, 4, 7, 10
  #debug concat(str(Counter, 0, 0), "\n")
#end

I think this syntax ought to be relatively easy to implement (compared to more “traditional” syntaxes, such as something like “for Counter = 1 to 10” or the C syntax, which would be a lot more complicated).

Of course this raises a couple of questions:

1) What happens if ‘Counter’ was already declared as an identifier? One of three possibilities comes to mind:

• The ‘Counter’ in the for-loop replaces the previous identifier, as a regular #local command would.

• The ‘Counter’ in the for-loop hides the identifier for the duration of the loop, and unhides it afterwards.

• A syntax error is given (ie. the identifier name must be unused).

2) Should the user be able to modify the counter variable from inside the body of the loop? Something like this comes to mind as viable:

// Prints the values 1, 2, 3, 9 and 10
#for(Counter, 1, 10)
  #debug concat(str(Counter, 0, 0), "\n")
  #if(Counter = 3) #local Counter = 8; #end
#end

Alternatively the counter variable could be read-only.

Additionally, it could be nice if #break could be used to immediately jump out of the current loop (either #while or #for).