POV-Ray 3.7-generated JPEG image output files do not conform to the JFIF standard. Most importantly, the files written do not use the standard YCbCr color model (they seem to use plain RGB instead), nor do they have a proper JFIF tag.

As a consequence, some software may be unable to read the generated JPEG files properly. In addition, it seems that POV-Ray mixes up the Red and Blue channels.

Setting File_Gamma=1.0 produces unexpectedly bright output files for most output file formats, as if File_Gamma was set to 2.2 instead.

The underlying problem is a bug that, when File_Gamma is set to exactly 1.0, causes the encoding gamma function to be undefined, which was not meant to happen in current versions, and instead was reserved for future versions to signal that a file-format-specific default encoding gamma should be used. The image file output handlers already support this, most of them choosing the sRGB transfer function, giving roughly the same output as setting File_Gamma=2.2.

As a preliminary workaround, users may want to set File_Gamma=1.02 (any value smaller than 0.99 or greater than 1.01 should do).

I can no longer run a Myfile.ini over a network, on a different computer.

Possiblely related to:

    http://bugs.povray.org/task/97   FS#97  (Forward-slash pathnames not fully supported in Windows version)

-
Cannot open INI file
‘\\STEPHEN-POVRAY\Bishop3d\Objects\Industrial_enclosure\Telco_enclosure_extra.ini’.
Failed to start render: Failed to parse INI file

The following line in the lathe1a.pov, lathe1b.pov, and lathe1c.pov appears to have an error in it.

  <3.6.9>, <4, 1.1>, <3.4, 2>, <3, 1>, <2, 1>,

Although it works in version 3.6, only in 3.7 does a render time error ocurr.

Scene source should be adjusted to the following

  <3.6, 0.9>, <4, 1.1>, <3.4, 2>, <3, 1>, <2, 1>,

Automatic removal of user-specified bounding boxes cannot be disabled in current POV-Ray 3.7 betas; the Remove_Bounds ini file setting and the +/-UR command line option are silently ignored.

OpenEXR output currently writes an alpha channel when Output_Alpha=off (-UA), and does not write an alpha channel when Output_Alpha=on (+UA), i.e. doing it just the wrong way round.

Reflections in multi-layered textures are broken in 3.7 betas, as can be demonstrated with the following scene showing two reflective hemispheres on a checkered plane:

camera {
  location  <1.0, 0.5, -4.0>
  direction 1.5*z
  right     x*image_width/image_height
  look_at   <0.0, 0.0,  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>]
    }
  }
}

light_source {
  <0, 0, 0>            // light's position (translated below)
  color rgb <1, 1, 1>  // light's color
  translate <-30, 30, -30>
}

default {
 finish { diffuse 0 ambient 0 specular 0 }
}

// ----------------------------------------

plane {               // checkered floor
  y, -1
  texture
  {
    pigment { checker color rgb 1 color blue 1 }
    finish{ diffuse 0.8 ambient 0.1 }
  }
}

// left hemisphere
intersection {
  sphere { 0, 1 }
  plane { x, -0.002 }
  texture {
    pigment { color rgb 1 }
    finish{ reflection { 0.5 } }
  }
  texture {
    pigment { color rgbt 1 }
    finish{ reflection { 0.4 } }
  }
  texture {
    pigment { color rgbt 1 }
    finish{ reflection { 0.1 } }
  }
}

// right hemisphere
intersection {
  sphere { 0, 1 }
  plane { -x, -0.002 }
  texture {
    pigment { color rgb 1 }
    finish{ reflection { 1.0 } }
  }
}

Note that the reflection parameters of the left, multi-layered hemisphere sum up to 1.0, i.e. the same value as used in the single layer in the right hemisphere.

The first attached file (test_3.6.2.png), rendered with POV-Ray 3.6.2, shows the expected output: Both hemispheres appear to have the same reflectivity.

The second attached file (test_3.7.0.beta37a.png), rendered with POV-Ray 3.7.0.beta.37a, shows a much brighter left (multi-layered) sphere.

As it turns out, in order to get the expected result with POV-Ray 3.7.0.beta.37a, the reflectivity of each layer must be divided by 3, 2 and 1, respectively (which obviously does not sum up to 1.0):

  ...
  texture {
    pigment { color rgb 1 }
    finish{ reflection { 0.5 / 3 } }
  }
  texture {
    pigment { color rgbt 1 }
    finish{ reflection { 0.4 / 2 } }
  }
  texture {
    pigment { color rgbt 1 }
    finish{ reflection { 0.1 / 1 } }
  }
  ...

Mosaic preview display didn’t work as expected, given these command line options: +sp64 +ep16. The preview was solid colored instead of the coarse preview that you’d expect.

I’ve tested a fix to unix/disp_sdl.cpp from clipka and it appears to work.

When using “filter all VALUE” with an image_map using a 4-bit (16-color) paletted bmp image, debug builds of POV-Ray fail with an assertion.

According to code analysis, other paletted image formats with <256 palette entries are also likely to be affected; similar assertion fails can be expected when using the “filter INDEX, VALUE” feature on such files with an index exceeding the palette size. “transmit” shows the same flaws.

Compiled on linux (revision #5066),
./configure COMPILED_BY=”###” –disable-io-restrictions

the command: povray –benchmark

is failing:
Failed to parse INI file

povray –version

I/O restrictions:          disabled
X Window display:          enabled (using SDL)
Supported image formats:   gif tga iff ppm pgm hdr png jpeg tiff openexr
Unsupported image formats: -

Build architecture:  x86_64-unknown-linux-gnu
Built/Optimized for: x86_64-unknown-linux-gnu (using -march=native)
Compiler vendor:     gnu
Compiler version:    g++ 4.4.3
Compiler flags:      -pipe -Wno-multichar -Wno-write-strings -fno-enforce-eh-specs -s -O3 -ffast-math -march=native -pthread 

A df3 file is written, with header 00 00 00 00 00 00 and no data (hypothetically valid df3 file).
This file is used as density file for media, using interpolation. This causes a crash once Pov-Ray starts rendering the pixels that contain media.
All pixels rendered before that render fine. Using no interpolation does not cause a crash.

Sample Scene:
#fopen out “random.df3” write
#write (out, uint16be <0,0,0>)
#fclose out

box{0,1 pigment{rgbt 1} hollow interior{media{
density{density_file df3 “random.df3” interpolate 1}}}} // interpolate 2 also crashes, interpolate 0 does not.

System: Win7 x64, 3.7 Beta 38

Include file golds.inc still provides warnings when parsed, a shame for a standard include file.
(colors.inc is ok, I did not test the other includes)

File '/usr/local/share/povray-3.7/include/golds.inc' line 118: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 119: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 129: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 130: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 140: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 141: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 151: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 152: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 162: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.
File '/usr/local/share/povray-3.7/include/golds.inc' line 163: Parse Warning:
 Expected pure RGB color expression, unexpected filter and transmit components
 will have no effect.

value is erroneously clipped to the range 0..1 before being displayed

There is a confirmed bug when writing jpg file format with the current linux build (beta39). when specifying +fj output format the following error occurs:

JPEG parameter struct mismatch: library thinks size is 372, caller
expects 376
JPEG parameter struct mismatch: library thinks size is 372, caller
expects 376
Render failed

this has been confirmed on ubuntu 10.4 and openSuSe 11.2 (assuming 32 bit version) as openSuSe 11.2 64-bit reports no problem

there has been a proposed fix to ~smp/source/base/image/jpeg.cpp that appears to work, however it requires some additional work to make it a platform (linux) and compiler (gcc) specific fix.

The text object isn’t working with /usr/share/fonts/truetype/freefont/FreeSans.ttf. Used to work - taken from an old .pov file of mine.

Rebuilt from
http://www.povray.org/redirect/www.povray.org/ftp/pub/povray/Official/Unix/povray-3.6.tar.bz2

$ povray +ifonttest.pov +ofonttest.png

Persistence of Vision™ Ray Tracer Version 3.6.1 (g++ 4.4.3 @
x86_64-unknown-linux-gnu)
This is an unofficial version compiled by:
darxus [at] chaosreignscom

.....

File: fonttest.pov Line: 8
Parse Warning: Character 101 (0×65) not found in /usr/share/fonts/truetype/freefont/FreeSans.ttf
File: fonttest.pov Line: 8
Parse Warning: Character 115 (0×73) not found in /usr/share/fonts/truetype/freefont/FreeSans.ttf

Verification that the problem is not in the .ttf file, this works (imagemagick):

convert -background lightblue -fill blue -pointsize 48 -font
/usr/share/fonts/truetype/freefont/FreeSans.ttf label:test fonttest.png

Problem verified when compiled from source on Ubuntu Lucid. Also exists in Ubuntu binaries from Lucid and Hardy.

Hi,

I have a problem with photons. The following stripped down code simulates a
slide projector:

#include "colors.inc"

global_settings {
  #if (1)   // switch photons on/off
    photons { count 1000000 }
  #end
}

camera { location <0, 0, 200> sky<0,1,0> look_at <0,200,-200> angle 90 }

// projection screen
plane { z, -200 texture { pigment { White } finish{ diffuse 1 ambient 0.1} } }

// slide
polygon {
  5, <0,0,0>, <1,0,0>,<1,1,0>,<0,1,0>,<0,0,0>
  pigment { image_map {jpeg "s7_0.9_320.jpg" interpolate 2 filter all 1.0 } }
  translate <-0.5, 0.2, -0.3>
  photons { target refraction on reflection off collect off }
}

// projector lamp
light_source { <0, 0, 0>  color <1,1,1> }

——————————————-

A point light source projects through a image_map onto a screen.

Without photons the projected image is ok:
http://img838.imageshack.us/i/test4woph.png/

With photons the left and right bottom corners of the image will be clipped:
http://img101.imageshack.us/i/test4wph.png/

The size of clipped corners depends on the y-offset in the translate command.

The povray Version is:
Persistence of Vision™ Ray Tracer Version 3.6.1 (Debian (x86_64-linux-gnu-g+
+ 4.3.3 @ x86_64-pc-linux-gnu))
(the 3.7 beta has the same problem)

I posted this question in the general news group and got an answer by Christian Froeschlin,
who could reproduce the problem and suggested as workaround to divide the slide into small stripes

http://news.povray.org/povray.general/thread/%3Cweb.4c972bdffcc128eac947b6de0%40news.povray.org%3E/

This works, but doesn’t explain the problem.

Does anyone have an idea, whats wrong?

Many thanks,
Corvin

the quick_color feature doesn’t work when +qN or Quality=N is set to 5 or below

From post in povray.general (circa 29 september 2010: “Maximum Resolution of Renders?”)

The ultimate goal would be a 41000×41000 image. However each time I have attempted to render that Pov-Ray has crashed on
me. Even when using a single, simple test object (a plain white sphere that
should use a single pixel). So I think this is running into a program limitation
at present.

It won’t be for the faint hearted: a 30500 x 30500 does still produces the bug, but you’d better have 24 GB of true ram to test it.
(it’s a render of a few “real” minutes if you do not swap, for any very quick scene (a 305 x 305 in 0.117s moved to 220s for 30500×30500 on my system when corrected))

With core-dumped enable, the issue is pointed in the creator of PixelContainer.
The problem is due to the resize() parameter: despite the parameter being a size_t (8 bytes long on 64bits), the computation ( h * w * 5 ) use unsigned int for h & w (and signed int for 5).

As a consequence, the value of resize is computed as a signed int... havoc might happen when the signed bit (#31) is propagated to the #63 to #32 of size_t... vector does not enjoy a negative value for resize (and destroy itself: no iterator on coming soon call! hence the crash when the values in the vector are to be initialised)

30500²: (in hex)

1 15 3C 71 50 floats
4 54 F1 C5 40 bytes

Basic solution: promote the 5 to an unsigned long, forcing the computation to happen on unsigned long, avoiding promotion of silly sign-bit, and keeping the resize’s value as a good number.

aka: resize( w * h * 5) becomes resize ( w * h * 5ul )

This solution has been tested and seems fine (it’s just that in base/image/image.cpp, there is a lot of resize()!).
For all resize(), the “ul” must be added. (and that means also that resize( w * h ) must be rewritten as ( w * h * 1ul ). )

[Original Title: “texture_map interpolation does not work correctly for some patterns”]

The below test scene should yield identical textures
T_STRAND1 and T_STRAND2 but this is not the case. Reported
and verified in

http://news.povray.org/povray.general/thread/%3C4cbd804b%241%40news.povray.org%3E/

The problem seems to affect bozo, bumps, dents, granite, spotted,
and maybe wrinkles. The problem was reported earlier in

http://news.povray.org/povray.beta-test/thread/%3C48112367%241%40news.povray.org%3E

with a comment that 3.6 gives the expected results

#declare C_STRAND = color rgb 1;

#declare C_CLEAR  = color rgb 0;

#declare T_STRAND = texture
{
  pigment {color C_STRAND}
}

#declare T_CLEAR = texture
{
  pigment {color C_CLEAR}
}

#declare T_STRANDS1 = texture
{
  pigment
  {
    granite scale 2 color_map
    {
      [0.0 color C_STRAND]
      [0.5 color C_CLEAR]
      [1.0 color C_CLEAR]
    }
  }
}

#declare T_STRANDS2 = texture
{
  granite scale 2 texture_map
  {
    [0.0 T_STRAND]
    [0.5 T_CLEAR]
    [1.0 T_CLEAR]
  }
}

plane
{
  z, 10
  texture {T_STRANDS1}
  //texture {T_STRANDS2}
} 

Bounding box computation for CSG intersection appears to be broken when one member is an arbitrarily transformed plane.

// +W640 +H480 +MB1

#include "transforms.inc"

camera {
  location  <-0.2, 0.5, -4.0>
  direction 1.5*z
  right     x*image_width/image_height
  look_at   <0.0, 0.0,  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>]
    }
  }
}

light_source {
  <0, 0, 0>            // light's position (translated below)
  color rgb <1, 1, 1>  // light's color
  translate <-30, 30, -30>
}

plane {
  y, -1
  pigment { color rgb <0.7,0.5,0.3> }
}

intersection {
  sphere {
    0.0, 1 }
  plane { -x, 0 transform { Shear_Trans(x,y+x*0.3,z) } }
  texture {
    pigment {
      radial
      frequency 8
      color_map {
        [0.00 color rgb <1.0,0.4,0.2> ]
        [0.33 color rgb <0.2,0.4,1.0> ]
        [0.66 color rgb <0.4,1.0,0.2> ]
        [1.00 color rgb <1.0,0.4,0.2> ]
      }
    }
    finish{
      specular 0.6
    }
  }
  rotate -y*5
}

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

See this thread for more information.

unixoptions.cpp has a getenv(”HOME”) that does an assignment without checking to see if getenv returns NULL.

This causes an immediate and unceremonious segfault in those situations where $HOME is not set such as in the case where povray is launched by a daemon.

Best solution might be to set the home to /tmp and print a warning message about $HOME not being set.

FileBackedPixelContainer uses a FILE* to manage the backing store and under Linux/Unix defines fseek64 to be a kind of incantation of lseek64.

Since fseek64 and fseek64 have return values that are logical opposites this causes an exception to be thrown.

Moreover since the buffer size on a FILE is quite a bit smaller than a line of pixels (in terms of bytes), mostly what’s being done in this function is a lot of sloshing of bytes that don’t do much... which is to say that the intended caching mechanism is getting a very low hit rate now that povray is working in 32×32 pixel per-thread chunks.

The cache miss problem and the volume of bytes read/written grows exponentially as the size of the image grows.

Attached is a replacement function that seems to be working well and should produce a performance increase even under Windows. I originally went with simply fixing the fseek/lseek problem but saw a 10% decrease in render time on 2048×1024-sized images when I made the cache target smaller.

Multi-textured blobs are broken with 3.7 beta 40 when used inside an intersection, as can be demonstrated by the following scene:

#default { texture { pigment { rgb 1 } } }

camera {
  right x*image_width/image_height
  location  <0,1.5,-4>
  look_at   <0,1,0>
}

light_source { <500,500,-500> color rgb 1 }

difference { blob {
  threshold 0.6
  sphere { < 0.75,   0,    0>, 1, 1 texture { pigment { color red 1 } } }
  sphere { <-0.375,  0.65, 0>, 1, 1 texture { pigment { color green 1 } } }
  sphere { <-0.375, -0.65, 0>, 1, 1 }
} }

With POV-Ray 3.7.0 beta 40, the entire blob is rendered with the default texture.

The same problem can be seen with “difference” or “merge” instead of “intersection”.

Omitting the CSG “envelope”, using “union”, or assigning the blob to a variable first and then using it inside an intersection, will yield the expected result.

POV-Ray 3.62 renders all variants as expected.

According to initial analysis, the problem appears to be caused by the dual use of the “MULTITEXTURE_FLAG”, which is used in CSG to indicate use of the “cutaway_textures” feature, and in blobs to indicate per-element texturing. (The same flag is also used in meshes to indicate per-face or per-vertex texturing, so similar problems are to expected there.)

My proposal is to use an entirely separate flag for the “cutaway_textures” feature (the blob and mesh can safely continue to share the MULTITEXTURE_FLAG).

If pretrace_start is set below pretrace_end, POV-Ray will run a high number of pretrace steps (without changing pretrace resolution).

‘povray -H10 -W20 myscene.pov’ will generate a file with a picture 10 pixels high and 20 pixels wide, BUT in the message pane it displays

Image resolution.....20 by 10 (rows 1 to 20, columns 1 to 10)

instead of

Image resolution.....20 by 10 (rows 1 to 10, columns 1 to 20)

or

Image resolution.....20 by 10 (columns 1 to 20, rows 1 to 10) 

polygon objects comprised of multiple “sub-polygons” don’t work properly if start/end points of sub-polygons do not exactly match, as can be demonstrated by the following code:

#default { texture { pigment { rgb 1 } finish { ambient 1.0} } }

camera {
  orthographic
  up 3.5*y
  right 3.5*x*image_width/image_height
  location  <0,0,-4>
  look_at   <0,0,0>
}

polygon { 8,
  // outer triangle
  0.70 * < cos(  0 *pi/180),sin(  0 *pi/180),0>
  0.70 * < cos(120 *pi/180),sin(120 *pi/180),0>
  0.70 * < cos(240 *pi/180),sin(240 *pi/180),0>
  0.70 * < cos(360 *pi/180),sin(360 *pi/180),0>

  // inner triangle
  0.35 * < cos(  0 *pi/180),sin(  0 *pi/180),0>
  0.35 * < cos(120 *pi/180),sin(120 *pi/180),0>
  0.35 * < cos(240 *pi/180),sin(240 *pi/180),0>
  0.35 * < cos(360 *pi/180),sin(360 *pi/180),0>
}

Note that the end points /should/ be identical. There are however some minor rounding differences, which mess up polygon computations. Compare with the following code, which leads to the desired results:

polygon { 8,
  // outer triangle
  0.70 * < cos(  0 *pi/180),sin(  0 *pi/180),0>
  0.70 * < cos(120 *pi/180),sin(120 *pi/180),0>
  0.70 * < cos(240 *pi/180),sin(240 *pi/180),0>
  0.70 * < cos(  0 *pi/180),sin(  0 *pi/180),0>

  // inner triangle
  0.35 * < cos(  0 *pi/180),sin(  0 *pi/180),0>
  0.35 * < cos(120 *pi/180),sin(120 *pi/180),0>
  0.35 * < cos(240 *pi/180),sin(240 *pi/180),0>
  0.35 * < cos(  0 *pi/180),sin(  0 *pi/180),0>
}

Code inspection shows that the polygon insideness testing code tests for precise equality of the points, whereas the general policy of POV-Ray is to accept slight rounding differences.

I rendered attached .pov file with both 3.62 and 3.7RC1, and got different output between them.
In 3.7RC1, it looks like no_reflection option of the black sphere doesn’t work.

Using interpolated image_maps in functions results in pixel-sized dot-artifacts when using the functions back into pigments.

This problem doesn’t shows using the same code on POV-Ray 3.6.

I qualified it as “low severity” because is not going to happen to most users: it will show only when using some advances techniques, for example when you want to decompose an image_map into the RGB components, perform operations, and mixing them back with an averaged pigment (example attached).

Trying to build povray-3.6 against png-1.5 fails spectacularly.

.../include/png.h:666: error: forward declaration of ‘struct png_info_def’ png_pov.cpp:1405: error: invalid use of undefined type ‘struct png_info_def’

appears a lot in the output.

The problem is that png-1.5 hides structure members from public view.

Note, this is not the same problem as  FS#144 .

povray +Imesh_camera.pov +Omesh_camera.png +FN +W800 +H600 produces a “Failed to parse command-line option” error. when I rename my pov source file to ess_mesh_camera.pov it runs fine. seems to be pointing to a clash with the +im option. i also had another file that renaming it got me going.

The documentation says:

“-J Sets aa-jitter off”

However, it seems to have no effect. -J0 will turn off jittering.

Given the following two statements, a missing closing brace in the function declaration fn should throw a parse exception; instead it causes a memory access violation when trying to use fn in the second delcaration:

#local fn = function { 
  pigment { image_map { png "MultiPassBlobs3.png" gamma 1 map_type 0 once }} 
#local clr = fn(0,0,0);

.../scenes/objects/fractal2.pov

in global_settings  "max_trace" should be "max_trace_level"

.../scenes/advanced/diffuse_back.pov

in global_settings  assumed_gamma statement should not be followed by a semicolon

.../scenes/advanced/blocks/stackernight.pov

in global_settings  "assummed_gamma" should be spelled "assumed_gamma"

.../scenes/portfolio/*.pov

in all files other than _empty.pov the parse stops at the lines containing "[frame_number-1]" I'm guessing it should be "[frame_number]-1"  

original post on povray.beta-test:

POV-Ray 3.7.0.RC3 on Slackware 13.0 x86_64.
I pointed povray to use the calibri.ttf font over on my Windows 7 partition.
The result is garbled - strange letters with accents appear instead of the
expected text. (KDE's kfontview opens calibri.ttf OK, with nothing strange).

Pointing povray to use other fonts of Win7, e.g. comic.ttf and arial.ttf, was
OK.

I solved the problem by pushing calibri.ttf through fontforge and resaving it
as mycalibri.ttf.

Cheers,
Peter

Confirmed with development version on Windows XP x64.

Possibly a similar problem as  FS#162 .

A scene of a hollow sphere viewed from the inside:

difference {
    sphere { 0, 100 }
    sphere { 0, 99 }
    pigment { rgb 1 }
    finish { ambient .4 }
}

global_settings {
    radiosity {
        error_bound .1
    }
}

Rendering produces dark splotches at the centers of the pretrace blocks, as shown in the attached image. Blocks rendered earlier have darker splotches. They also differ in shape between renders even with +HR (but not with +WT1).

Turning “always_sample” on, changing “pretrace_end” to 0.01, or increasing “count” past 1000 makes them imperceptibly faint (they can still be seen by increasing image contrast).

This is possibly a bug, as 3.6 doesn’t produce these artifacts regardless of additional settings.

povray.beta-test thread

#macro A()
    #local f = function { x }
#end

#local f = 1;
A()

This gives:

File 'bug.pov' line 2: Parse Error: Attempted to redefine float identifier as
 function identifier.

The problem is that this makes using functions in library macros difficult. Basically, they must have a globally unique name that’s not used in any of the macros or files that call the macros. #undef doesn’t really help, because it destroys the identifier in the calling scope.

For example, one of the macros in the standard include files names a function “fn”, so this doesn’t work:

#include "transforms.inc"

#local fn = 42; // fnord?
#local fn_pos = vtransform(x, transform { rotate 30*y } );

The reason for this restriction is explained in Parse_RValue in source/backend/parser/parse.cpp:

    // Do NOT allow to redefine functions! [trf]
    //   #declare foo = function(x) { x }
    //   #declare foo = function(x) { foo(x) } // Error!
    // Reason: Code like this would be unreadable but possible. Is it
    // a recursive function or not? - It is not recursive because the
    // foo in the second line refers to the first function, which is
    // not logical. Further, recursion is not supported in POV-Ray 3.5
    // anyway. However, allowing such code now would cause problems
    // implementing recursive functions after POV-Ray 3.5!

In this case the restriction is applied too broadly: it should be safe to redefine anything other than a function to a function and still avoid it looking like recursion. In fact, there’s a restriction in Parse_Declare specifically to prevent redefining functions.

#macro A()
  #local foo = function { x }
  foo
#end

#local bar = A();

This causes either a segfault, corruption detected by malloc, or “Parse Error: Unknown user defined function”.

After some debugging I think this is what happens.

In source/backend/parser/parse.cpp, Parser::Parse_RValue is called to define the value of bar. Get_Token is called, which invokes A() and which ultimately returns foo as a FUNCT_ID_TOKEN. This token is handled by CASE_VECTOR in Parse_RValue. The relevant clause calls Parse_Unknown_Vector to parse additional tokens (e.g. “foo ( 1 )”). There aren’t any other tokens, but in the process of determining that, #end is reached and Return_From_Macro destroys the symbol table of A, including foo.

So by the time the CASE_VECTOR clause decides that foo is a function identifier that should be copied, the function is destroyed (both the function itself and its number in the symbol table). So here:

    Temp_Data  = (void *) Copy_Identifier((void *)*Token.DataPtr,*Token.NumberPtr);

if *Token.DataPtr (in this case, a function index) was already overwritten, we get “Unknown user defined function”; if it still has the valid function number, it increments the reference count of the function (which has already been freed) back from 0, and we get a double-free later.

A similar problem occurs when foo is a spline.

A tentative patch for the function case is attached.

in change #3319, csg got a new computation for its weighted textures.

But I’m confused by the computation of the weight: (circa end of csg.cpp file)

COLC weight = 1.0f / min(COLC(textures.size() - firstinserted), 1.0f);

I would have used a max() rather than a min().

It is transparent when there is only one texture, but:

• should there be no texture (an error...): it would be a division by 0
• should there be more than 1, the weight of each would be 1. which is without consequence UNLESS there is already some other textures in the list. The right value (from previous code) was 1/n

Or did I get a confusion about min() ?

min(0,1) == 0
min(4,1) == 1

Using max would protect against the division by 0 and the right value when multiple textures are used.

Any thought ?

UV-mapped textures for parametrics are broken in POV-Ray 3.70 RC3, in cases where two (or more) parametrics overlap in a scene.

In the following scene, note how the texture per se is always taken properly from whichever parametric is in front, while the UV coordinates are erroneously taken always from the red parametric where both overlap, no matter whether it is in front or back.

camera {
  location  <0.0, 1.5, -3.0>
  direction 1.5*z
  right     x*image_width/image_height
  look_at   0
}

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

#declare Param = parametric {
  function { u*v*sin (15*v) },
  function { v },
  function { u*v*cos (15*v) }
  0, 1
  contained_by { box { -1,1 } }
  accuracy 0.002
  precompute 15 x,y,z
  rotate 180*x
  translate  <0.3,0.5,0>
}

object {
  Param
  uv_mapping
  texture {
    pigment {
      gradient x frequency 3
      color_map {
        [0 color red .5 ]
        [1 color red 1 ]
      }
    }
  }
}

object {
  Param
  uv_mapping
  texture {
    pigment {
      gradient x frequency 7
      color_map {
        [0 color green .5 ]
        [1 color green 1 ]
      }
    }
  }
  rotate y*180
}

POV-Ray 3.62 renders the scene properly.

As this bug has been found during code inspection, the uderlying cause has already been identified; I’m currently working on a fix.

Hello,

this bug report relates to this thread: http://news.povray.org/povray.beta-test/thread/%3Cweb.4e0064d9a3970d212b256d410%40news.povray.org%3E/

In /unix/unixoptions.cpp around line 817:

while ( !Stream.eof() )
{
	// get and preprocess line
	std::getline(Stream, line);
	line = pre_process_conf_line(line);
	++line_number;
	// skip empty line
	if(line.length() == 0)
		continue;
        [...]
}

`Stream.eof()` could never be true as well as `line.length()` always can be zero, leading to an endless loop. In my case, the problem occurred due to my ~/.povray/3.7/povray.conf being a directory instead of a file.

To fix the problem, one has to consolidate this loop by not only checking for eofbit, but also for failbit and badbit of `Stream`. The getline() method on a directory does not set the eofbit, but it sets fail and bad (test: http://codepad.org/RiZGo3ia). According to http://www.cplusplus.com/reference/iostream/ios/operatornot/ fail and bad can be checked for by `!Stream`. A simple `if (!Stream) break;` within the loop fixes the problem (patch file attached).

Are there more missing checks on iostreams like this in the code? :) They should definitely be fixed.

Furthermore, one could think about using the boost filesystem library to be able to distinguish files and directories to provide good error messages.

Hope that helps,

Jan-Philip Gehrcke

I tried to use 3.7 RC3. This was my first time with 3.7.

I got source, configured and compiled it and installed into Debian with checkinstall. And then I tried to use it. First run was with -benchmark (it took about 9 minutes, ok). Then I tried very simple scene:

rekcahx@oah:~/pov$ povray +Iaa.pov
povray: This is a RELEASE CANDIDATE version of POV-Ray. General distribution is discouraged.
Failed to parse command-line option

I tried to debug with strace:

rekcahx@oah:~/pov$ strace -o debug.strace povray +Iaa.pov
povray: This is a RELEASE CANDIDATE version of POV-Ray. General distribution is discouraged.
Persistence of Vision™ Ray Tracer Version 3.7.0.RC3 (g++ 4.6.1 @
x86_64-unknown-linux-gnu)
This is a release candidate of POV-Ray version 3.7.0.
General distribution is strongly discouraged.

POV-Ray is based on DKBTrace 2.12 by David K. Buck & Aaron A. Collins
Copyright 1991-2003 Persistence of Vision Team
Copyright 2003-2011 Persistence of Vision Raytracer Pty. Ltd.

Primary POV-Ray 3.7 Architects/Developers: (Alphabetically)

Chris Cason         Thorsten Froehlich  Christoph Lipka   

With Assistance From: (Alphabetically)

Nicolas Calimet     James Holsenback    Christoph Hormann   Nathan Kopp       
Juha Nieminen     

Past Contributors: (Alphabetically)

Steve Anger         Eric Barish         Dieter Bayer        David K. Buck     
Nicolas Calimet     Chris Cason         Aaron A. Collins    Chris Dailey      
Steve Demlow        Andreas Dilger      Alexander Enzmann   Dan Farmer        
Thorsten Froehlich  Mark Gordon         James Holsenback    Christoph Hormann 
Mike Hough          Chris Huff          Kari Kivisalo       Nathan Kopp       
Lutz Kretzschmar    Christoph Lipka     Jochen Lippert      Pascal Massimino  
Jim McElhiney       Douglas Muir        Juha Nieminen       Ron Parker        
Bill Pulver         Eduard Schwan       Wlodzimierz Skiba   Robert Skinner    
Yvo Smellenbergh    Zsolt Szalavari     Scott Taylor        Massimo Valentini 
Timothy Wegner      Drew Wells          Chris Young       

Other contributors are listed in the documentation.

Support libraries used by POV-Ray:

ZLib 1.2.3.4, Copyright 1995-1998 Jean-loup Gailly and Mark Adler
LibPNG 1.2.44, Copyright 1998-2002 Glenn Randers-Pehrson
LibJPEG 62, Copyright 1998 Thomas G. Lane
LibTIFF 3.9.5, Copyright 1988-1997 Sam Leffler, 1991-1997 SGI
Boost 1.46, http://www.boost.org/
OpenEXR, Copyright (c) 2004-2007, Industrial Light & Magic.

Parser Options

Input file: aa.pov
Remove bounds........On 
Split unions.........Off
Library paths:
  /usr/share/povray
  /usr/share/povray/ini
  /usr/share/povray/include
Clock value:    0.000  (Animation off)

Image Output Options

Image resolution.....320 by 240 (rows 1 to 240, columns 1 to 320).
Output file..........aa.png, 24 bpp PNG
Dithering............Off
Graphic display......Off
Mosaic preview.......Off
Continued trace......Off

Information Output Options

All Streams to console..........On 
Debug Stream to console.........On 
Fatal Stream to console.........On 
Render Stream to console........On 
Statistics Stream to console....On 
Warning Stream to console.......On 

[Parsing...]

Parse Time:       0 hours  0 minutes  0 seconds (0.001 seconds)
            using 1 thread(s) with 0.000 CPU-seconds total
Bounding Time:    0 hours  0 minutes  0 seconds (0.000 seconds)
            using 1 thread(s) with 0.000 CPU-seconds total

Quality:  9
Bounding boxes.......On   Bounding threshold: 3
Antialiasing.........Off

[Rendering...]

Photon Time:      No photons
Radiosity Time:   No radiosity
Trace Time:       0 hours  0 minutes  0 seconds (0.016 seconds)
            using 4 thread(s) with 0.036 CPU-seconds total

I/O restrictions:          disabled
X Window display:          enabled (using SDL)
Supported image formats:   gif tga iff ppm pgm hdr png jpeg tiff openexr
Unsupported image formats: -

Build architecture:  x86_64-unknown-linux-gnu
Built/Optimized for: x86_64-unknown-linux-gnu (using -march=native)
Compiler vendor:     gnu
Compiler version:    g++ 4.6.1
Compiler flags:      -pipe -Wno-multichar -Wno-write-strings -fno-enforce-eh-specs -s -O3 -ffast-math -march=native -pthread

Certain types of errors are being reported twice. For example:

Parse Error: Expected ‘numeric expression’, } found instead
Parse Error: Expected ‘object’, undeclared identifier ‘foo’

The first error was a user typo when not enough parameters were specified, and the later when calling a yet to be declared object.

During investigation it was also discovered that improperly formed scale statements also produced the double error report: <scale 1,0.5,1>

Verified on linux and windows platforms.

in the sample scenes, animations/raddem/raddem.ini is not parsable by current versions of povray. (3.7RC3 and upto #5476)

Radiosity= is a gone away option.(from a bit of time in the 3.7 branch)

Lines 1217, 1241 and 1242 of benchmark.cpp must be change to use #declare instead of local for A and its elements.
(because A is returned by the macro)

	"#macro L_GetVN(ResSpl)\n"
	"   #local I = 0;\n"
	"   #declare A = array[ResSpl+1][2]\n"                      //  <============== this is line 1217
	"   #while (I<=ResSpl)\n"
	"      #local P0 = 0+<FnA(I/ResSpl), I/ResSpl, 0>;\n"
	"      #if (P0.x=0 & P0.z=0)\n"
	"         #local P0 = <1e-25,P0.y,1e-25>;\n"
	"      #end\n"
	"      #if (I=0)\n"
	"         #local P1 = 0+<FnA(((I-0.5)/ResSpl)), I/ResSpl, 0>;\n"
	"         #local P2 = 0+<FnA(((I+0.5)/ResSpl)), I/ResSpl, 0>;\n"
	"      #else\n"
	"         #local P1 = P2;\n"
	"         #local P2 = 0+<FnA(((I+0.5)/ResSpl)), I/ResSpl, 0>;\n"
	"      #end\n"
	"      #local P3 = vrotate(P0,<0,1,0>);\n"
	"      #local P4 = vrotate(P0,<0,-1,0>);\n"
	"      #local B1 = P4-P0;\n"
	"      #local B2 = P2-P0;\n"
	"      #local B3 = P3-P0;\n"
	"      #local B4 = P1-P0;\n"
	"      #local N1 = vcross(B1,B2);\n"
	"      #local N2 = vcross(B2,B3);\n"
	"      #local N3 = vcross(B3,B4);\n"
	"      #local N4 = vcross(B4,B1);\n"
	"      #local N = vnormalize((N1+N2+N3+N4)*-1);\n"
	"      #declare A[I][0] = P0;\n"                               // <============== this is line 1241
	"      #declare A[I][1] = N;\n"
	"      #local I = I+1;\n"
	"   #end\n"
	"   A\n"
	"#end\n"

Same update should also be reported into the distributed scene benchmark.pov

The following SDL code causes a hard crash during parsing if _3024_dot_dat is undefined:

light_source {
    <0, 0, 0>
    color rgb 0.5*<1,0.905882,0.211765>
    fade_distance 500
    fade_power 1.6
    looks_like {_3024_dot_dat texture {
        pigment { rgbf <1,0.905882,0.211765,0.90> }
        finish { ambient 0.6 diffuse 0 phong 0.5 phong_size 40
            reflection 0.9
            refraction 1 ior 1.25
            }
        }
}    } 

Thin tori exhibit artifacts in 3.7.0 RC3 when the camera is placed inside the torus close to its “center plane”, as can be demonstrated with the following scene:

camera {
  location  <0.0, 0.0, -0.5>
  direction 1.5*z
  right     x*image_width/image_height
  look_at   <0.0, 0.0,  0.0>
  angle 1
}

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

torus {
  1, 0.001
  texture { pigment { color red 1 } }
}

The following scene reders differently with POV-Ray 3.7.0.RC3 than with POV-Ray 3.6.2:

camera
{
    right x*image_width/image_height
    location  <0, 0, -5>
    look_at   <0, 0, 0>
}

light_source
{
    <0,0,0>
    color rgb 1
    looks_like
    {
        box {
            <-1,-1,-0.1>, <1,1,0.1>
            pigment { wood }
            finish { ambient 5.0 diffuse 0 specular 0 phong 0 reflection 0 }
            scale 0.5
        }
    }
    translate <1,0,0>
}

plane
{
    <0, 1, 0>, -1
    texture
    {
        pigment { color rgb <0.5, 0.5, 0.55> }
        finish { specular 1.0 }
    }
}

See attachments for the output. As can be seen, POV-Ray 3.7 does translate the shape of the looks_like object along with the light source, but fails to translate the textures.

parser fails to report when an illegal map_type is used. For example map_type 10 and map_type 100 doesn’t produce an error

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.