POV-Ray

Recruit version 3.7 documentation editors from the users community.

The version 3.6 documentation needs to be updated to suit the changes for version 3.7.

Beta 32, compiled from source on Linux/Ubuntu, amd64.

The random “window display lock” is back.
(as the previous “solution” was to get no window display usable, that’s not so bad).

What is it: sometime, when the rendering window is activated, povray just draw the frame
of the window, paint it black, does not display anything else but seems to perform the
rendering in separate threads. Whenever the mouse move over the frame of the window, it
unlock the updating process and big parts of the rendered image pop up.

What it is not fine: if you do not move the mouse over the window, povray will just stall.
This is more a problem for animation rendering, as getting the display might be a wanted
bonus to monitor the rendering images, and you just fall into that lock: your expected
night rendering could very well be suspended on the first frame.
Moreover, the “move the mouse over” works only for local display. In previous beta (not
yet checked with 32), with a remote display, there was no way to unlock povray.

Develop MediWiki extension to extract documentation sets from the POV-Wiki.

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

Some sample scenes are no longer up-to-date, causing warnings, and should be fixed. For instance, the advanced/benchmark scene still includes “Buffer_Output=Off” and “Buffer_Size=0” in its .ini file. This should be checked systematically, and fixed as appropriate.

If you abort a render with ^C, Povray exits with a ‘success’ error code.

To test:

povray scene.ini
(^C to abort it)
echo $?

Right now 0 is returned (’success’). A non-zero value should be returned (’failure’).

This is particularly important for scripting, where command lines like:

povray scene.ini && halt

...can be used. I only want the halt to be executed if the scene renders successfully. If I change my mind and ^C it, I don’t want the machine to shut down!

The following scene shows how photons are “boosted” by pass_through objects; removing one of the boxes will reduce the effect; the effect can be seen with 3.6 as well as current betas:

global_settings {
  max_trace_level 10 // makes a difference!
  photons { spacing 0.02 }
}

camera {
  right x*image_width/image_height
  location  <0,2.6,-10>
  look_at   <0,0.75,0>
}

light_source {
  <500,500,150>
  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 <1.0, 0.8, 0.6> } }
}

#declare M_Glass=
material {
  texture {
    pigment {rgbt 1}
    finish {
      ambient 0.0
      diffuse 0.05
      specular 0.6
      roughness 0.005
      reflection { 0.1, 1.0 fresnel on }
      conserve_energy
    }
  }
  interior {
    ior 1.5
    fade_power 1001
    fade_distance 0.9
    fade_color <0.5,0.8,0.6>
  }
}


sphere {
  <1.1,1,-1.3>, 1
  material { M_Glass }
  photons {
    target 1.0
    refraction on
    reflection on
  }
}

cylinder {
  <-1.2,0.01,0.8>, <-1.2,2.5,0.8>, 1
  material { M_Glass }
  photons {  // photon block for an object
    target 1.0
    refraction on
    reflection on
  }
}

box {
  <2.4,0,-2.3>, <2.6,4,-0.3>
  material { M_Glass }
  photons { pass_through }
}

box {
  <2.9,0,-2.3>, <3.1,4,-0.3>
  material { M_Glass }
  photons { pass_through }
}

There should be a table of contents on each page of the documentation, or at least on the very long pages. Scrolling through the entire page to figure out what topics are covered sucks.

20 library paths is a bit small given the sheer number of include files I’ve collected over the years. An increase in the number, and/or the ability to include wildcards in the search path, would be great.

The documentation assumes that INI files (as well as the command line!) are parsed and processed instantly. This no longer holds true for POV-Ray 3.7, where parsing INI files (and the command line) and processing it are separate operations that occur at different times. As such, one consequence is that INI file options only take effect after reading the whole INI file, and possibly later.

As such, documentation statements such as <http://www.povray.org/documentation/view/3.6.1/222/>
“Note: that these options take effect immediately when specified. Obviously any error or warning messages that might occur before the option is read will not be affected.”

Are no longer correct. It needs to be explained that options only take effect after the INI file has been read. An error in the INi file causes other options _not_ to take effect because reading of the INi file is aborted prematurely.

clipka anonymous@anonymous.org wrote:
> Am 29.06.2010 04:27, schrieb jberry02:
>
> > First, note that this is the Windows version.
> > Second the issue is not with opening the ini file, but with opening the scene
> > file from within the ini file.
> >
> > I have a scene.ini file, that has a line:
> >
> > Input_File_Name=scene
> >
> > under POV-Ray 3.5 *and* POV-Ray 3.6, the scene defined in the file scene.pov is
> > rendered properly using the parameters specified in the scene.ini file. The ini
> > file is opened from the POV-Ray GUI, and run using the “Run” button.
> >
> > under POV-Ray 3.7, I get an error - I originally thought that it was simply not
> > looking for scene.pov (i.e., it wasn’t adding the .pov extension when trying to
> > open the scene file), but looking closer the error is *actually*:
> >
> > Input file ‘C:\[...]\scene’ not found; cannot determine I/O permission for
> > write.
> > Failed to start render: Cannot open file.
> >
> > In other words, it appears that the problem is that it isn’t adding the default
> > ..pov extension when it is trying to do the I/O permission check. I do not have
> > any special I/O permisssions configured for any version of POV-Ray (I get the
> > pop-up dialogs), and this is a change in behavior from 3.6 to the current beta
> > of 3.7. The scene.pov file is not in any of the POV-Ray directories - it is in
> > a separate tree where I keep my scene files.
>
> Having looked at it in a debugger, I can confirm that there is a
> problem, and that you don’t seem to be far off the mark:
>
> The error occurs when POV-Ray tries to determine the I/O permissions for
> the /output/ file. If that isn’t explicitly specified with a path,
> POV-Ray will try to get the path from the input file; however, it will
> take the unprocessed parameter (in the sample case “scene”) rather than
> the file name POV-Ray makes of it (”scene.pov”), and then attempts to
> get the full /long/ path name of the file (remember the good old 8.3
> filenames for compatibility with 16-bit programs?), which only works
> when the file exists.
>
> Would you mind submitting a bug report to <http://bugs.povray.org>?

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.

Currently, output image is buffered using POV-Ray’s RGBFT color model and floating point values, leading to a memory consumption of 20 bit per pixel. This is an unproportionally large memory footprint, given that the only further processing performed on the buffered data is conversion of the data to the desired output file format, which will typically use only 3 bytes per pixel (at most 12 bit per pixel).

The situation can be improved by choosing the output image buffer container based on the desired output file format and parameters. To this end, the following code changes should be made:

• Bundle image file format handler code into classes (typically one per file format)
• Include a method to determine the best data container type for the image buffer
• Instantiate the desired image file format handler object prior to rendering, querying the handler object for an image buffer

In addition to picking a suitable image data container from the already existing palette, careful design might also allow to use custom containers to directly pass the data to a library (in case the library provides its own buffering anyway), or write it directly to the output file (e.g. when writing image data to stdout). To make this compatible with multithreaded rendering, the following changes would have to be made:

• Add code to detect when a row of SMP blocks has been finished, and call a certain method on the image handler object
• Design the custom containers in such a way that they can buffer any number of unfinished SMP block rows as needed

Keyword Completion does not work for several names.
I miss it for animation related names like frame_number or final_frame.

Typing “fram{TAB}” just inserts a TAB character after “fram” instead of completing it to frame_number.

Independently of that bug, typing {TAB} repeatedly does not cycle through possible names:
“fr{TAB}” gives “frequency” and “fresnel” and that’s all.

In version 3.6 it worked well.

My system is Windows 7 64bit and PovRay is 3.7.0.RC3.msvc9.win64

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

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.

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)) )

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 aborting a render when there are unfinished blocks among finished ones, under certain conditions some of those blocks are skipped when continuing the render later.

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

POV-Ray 3.6.2 has the same problem (can’t test for 3.6.1).

// +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
}

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.

In unix distribution these scripts

• allscene.sh
• allanim.sh
• porfolio.sh

have the variable VERSION set to 3.6

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?

The commands:

povray +i /home/ronis/Nm=500/povray.00001.pov

or

povray +i/home/ronis/Nm=500/povray.00001.pov

fail with: povray: this pre-release version of POV-Ray for Unix expires in 2 day(s) and 1 hour(s)
Failed to parse command-line option

Going to the directory and simply running: povray +i povray.00001.pov
works.

I came across this by accident trying to get emac’s povray mode to work; apparently it passes the full path name to povray.

I don’t think there is a problem in 3.6.1

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

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 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.

Trace level is not handled properly with blobs using per-component reflective or refractive textures, leading to lockups. Stepping through the code, it seems that POV-Ray fails to properly mark the blob object as increasing the trace level.

(Until this bug is fixed, the issue can be worked around in most cases by assigning a reflective texture to the blob as a whole.)

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.

Add a way to get and set font metrics.

Attached an image that shows what I’m talking about.

Thanks!!

Improve native support for 2D primitives. Ideally a 1:1 mapping of SVG primitives/shapes. They go a long way to making diagrams look a lot better. Having to create image maps based on externally created bitmaps slows the workflow down a lot!

The configure script for unix uses a dumb string compare to test whether libpng version is 1.2.5 or higher, leading it to reject (for instance) libpng 1.2.27 and unnecessarily compile and statically link the older libpng version it comes with.

Scenes starting with the incorrect syntax

version 3.7;

do not raise an error, instead they render a black screen with an empty scene warning.
#version should fail with an error when the # is missing.