POV-Ray

At the moment in the Poly Object the maximum power is 15. The mathematics for converting the three parametric equations for x, y and z into a formula for the Poly Object require that the equations are squared several times given max-powers of 4, 8 and even 16. I’ve one eqaution that needs power 16. At the moment this is just one power short. Please raise this to 16. That’s all I ask for.

Suggestion:

In file screen.inc, have macro Screen_Object() set no_radiosity on the object.

There are times when scaling an entire scene up or down is difficult or just not feasible.

One suggestion is a global_settings option.

Also, I’ve noticed that in some situations, such as interactions between certain transparent objects, the epsilon seems to kick in quite early. Perhaps there could be situational or contextual epsilons, such as the “tolerance” of sphere_sweep or the “accuracy” of isosurface.

When I try to re-render the insert menu bitmaps,on the Windows version 3.7b36 there is an error with the
Shapes.pov file.
line 474: Parse Error: Unexpected additional ‘.’ in floating-point number

line 474 is:

<2.6, 0>, <3.6.9>, <4, 1.1>, <3.4, 2>, <3, 1>, <2, 1>

The second vector has two decimal points
Change to <3.6,.9>

The current Windows version of POV-Ray does not fully support forward slashes in pathnames; specifically, POV-Ray fails to recognize drive letters when followed by a forward slash, e.g. “C:/foo/bar.pov” or “C:/foo\bar.pov”, rejecting such names for e.g. Input_File_Name.

How to do it: (with raddem.ini & raddem.pov from distributed scenes, copied in local directory)

1. run “povray raddem.ini” until frame 6 or more (irrelevant, at least frame 1 & 2 are needed), interrupt the render.
2. restart “povray raddem.ini +C”

It fails at frame 2 with
Possible Parse Error: Cannot find file ‘raddem.pov’, even after trying to append
file type extension.
Parse Error: Cannot open input file.
Fatal error in parser: Cannot parse input.
Render failed

The detection of frame 1 is fine.

I’ve got an ini file that looks like this:

Post_Frame_Return=U
Post_Frame_Command=notepad.exe

And when I render a scene using that ini file, it renders correctly but then
gives me this error:

Render halted because the post-frame shell-out (’notepad.exe’) requested POV-Ray
to generate a user abort.
Render failed

.....and it doesn’t open notepad.

I’ve unchecked the “Disable Starting Other Programs” and I’ve tried various
variations on what exe to run and whether to do it Pre/Post Frame/Scene, and
nothing has worked.

Compiling the sources with clang instead of g++ (on ubuntu 12.10 with boost 1.50)

./configure COMPILED_BY=”your name here <also@email>” LIBS=-lboost_system –disable-io-restrictions CC=clang CXX=clang

there is a few warnings that catch the eyes (and other as well that I dismiss so far, such as cases not covered in switch and empty body in if, or extraneous parentheses in tests):

support/randomsequences.cpp:553:15: warning: field is uninitialized when used here [-Wuninitialized]
                        startIndex(startIndex)
                                   ^
support/randomsequences.cpp:553:15: warning: field is uninitialized when used here [-Wuninitialized]
support/randomsequences.cpp:974:40: note: in instantiation of member function 'pov::PrecomputedNumberGenerator<int>::PrecomputedNumberGenerator' requested here
        SeedableIntGeneratorPtr generator(new PrecomputedIntGenerator(factory, count));
                                              ^
support/randomsequences.cpp:553:15: warning: field is uninitialized when used here [-Wuninitialized]
                        startIndex(startIndex)
                                   ^
support/randomsequences.cpp:984:43: note: in instantiation of member function 'pov::PrecomputedNumberGenerator<double>::PrecomputedNumberGenerator' requested here
        SeedableDoubleGeneratorPtr generator(new PrecomputedDoubleGenerator(factory, count));
                                                 ^
support/randomsequences.cpp:553:15: warning: field is uninitialized when used here [-Wuninitialized]
                        startIndex(startIndex)
                                   ^
support/randomsequences.cpp:1011:43: note: in instantiation of member function 'pov::PrecomputedNumberGenerator<pov::Vector3d>::PrecomputedNumberGenerator' requested here
                return SequentialVectorGeneratorPtr(new PrecomputedVectorGenerator(factory, count));
                                                        ^
support/randomsequences.cpp:553:15: warning: field is uninitialized when used here [-Wuninitialized]
                        startIndex(startIndex)
                                   ^
support/randomsequences.cpp:1056:45: note: in instantiation of member function 'pov::PrecomputedNumberGenerator<pov::Vector2d>::PrecomputedNumberGenerator' requested here
                return SequentialVector2dGeneratorPtr(new PrecomputedVector2dGenerator(factory, count));

Self referencing member in creator does not seems to be great for a reproducible pseudorandom generator (some compiler/architecture might force to 0, other might not... seems bad karma).

                           
             povmscpp.cpp:1875:4: warning: delete called on 'POVMS_MessageReceiver::HandlerOO' that is abstract but has non-virtual destructor [-Wdelete-non-virtual-dtor]
                        delete nodeptr->handleroo;
                        ^
povmscpp.cpp:1877:4: warning: delete called on 'POVMS_MessageReceiver::Handler' that is abstract but has non-virtual destructor [-Wdelete-non-virtual-dtor]
                        delete nodeptr->handler;
                        ^

Maybe just a missing keyword (virtual) in the header file ? Or is it harder ?

shelloutprocessing.cpp:260:28: warning: expression result unused [-Wunused-value]
        for (s = str.c_str(); *s; *s++)
                                  ^~~~

Why “*s++” ? why not just “s++” ?

renderfrontend.cpp:1165:57: warning: trigraph ignored [-Wtrigraphs]
                                        default:                                    t = "(???)";                            break;
 

I guess it’s not an intended trigraph. Might nevertheless perturb some compiler/result.

In POV-Ray’s documentation it says:

3.2.2.2 Max Image Buffer Memory
This INI parameter sets the number of megabytes of RAM to allow for output image caching. If the output image happens to use more than this, a file backed temporary image is used instead.

I used this INI file option because the default value (128 megabytes) seemed insufficient. pov-state backend files were always created and they were remarkably larger than the resulting image (bmp) files. Consequently, I set

Max_Image_Buffer_Memory = 3096

in the INI file so that POV-Ray should, according to the documentation, now be able to use 3 gigabytes of RAM so no backend temporary file would be needed at all (this large they were never).

However, while POV-Ray was rendering I still discovered a pov-state file and it still had a similar size.

Now I am confused: did the INI option not work or have I misunderstood the documentation? If the former is the case, that would be a bug, wouldn’t it?

I tested both under Windows XP and Debian 6.0.5.

After a long parse period and a relatively quick rendering, POVray gets stuck at 99% when rendering the attached file.

Rendered at 6144x3072px with antialiasing set to 0.3.

Can anyone confirm?

3.6x only bug with easy/known fix. Error message: “Identifier expected, incomplete function call or spline call found instead.” caused by token counter variable using the wrong special value. The symptom occurs when using a lot of splines. See this thread for details.

(I am using a self-compiled special build because I use a lot of splines in 3.6 but would rather use an official 3.6)

The parser is missing extra period characters when it parses a float as a vector component.

#local sample = <0.0.0.1,0,0>;

Doesn’t generate an error, but should.

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

Reported by cshake + pov @ gmail . com in p.beta-test, 14th december 2009

I wrote a simple script to convert fractint color maps to povray color_maps so I could use ApoMap to make nice fractal colors for pov, but I ran into
“Parse Error: Blend_Map too long.” The map has entries from 0/255 up to 255/255 (inclusive). I looked up the documentation which says that color_maps can have from 2 to 256 entries, and this is exactly 256 entries.
I’m posting this in beta-test because I assume that the documentation is correct for v3.6, and that a previous version can handle 256 entries.

The following code is erroneously accepted by POV-Ray (tested with 3.7.0.beta.36):

pigment{
  slope { x }
  checker
}

The result is a checker pattern.

Apparently there is an EXIT statement missing in the slope-pattern parsing code in parstxtr.cpp.

The #switch directive isn’t parsing correctly. In the following construct NO warning or error is generated:

#switch (RF)

case (0)
	rotate z*355
#break
case (144)
	rotate z*7.5
#break
case (216)
	rotate z*5
#break

#end

RF is a variable passed to the macro in which this construct resides. The first ‘case’ action IS executed, but none of the others are on successive calls to the macro. If I properly add ‘#’ to the second case the 1st and 2nd condition are executed but not the last. If ‘#’ is REMOVED from any of the break directives an error is generated and parsing halts.

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

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.

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.

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);

#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.

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

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.

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
            }
        }
}    } 

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

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.

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

A pigment statement not wrapped in a texture statement does not properly override a pigment previously defined for the object. In the following SDL code:

  #declare PLANE = plane { y,0
    texture {
      pigment { checker color rgb 1 color rgb 0 scale 0.1 }
  } }
  object { PLANE
    pigment { checker color red 1 color blue 1 scale 1.0 }
  }

the scaling of the pigment previously specified for the PLANE object is retained for the new pigment. Compare:

  #declare PLANE = plane { y,0
    texture {
      pigment { checker color rgb 1 color rgb 0 scale 0.1 }
  } }
  object { PLANE
    texture {
      pigment { checker color red 1 color blue 1 scale 1.0 }
  } }

which behaves as expected.

The issue has been around at least since POV-Ray 3.6.2.

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)) )

#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 }

For some particularly “heavy” SDL scripts, it might be desirable to override (or complement) the standard “Parsing 47110815K tokens” progress information with some more helpful custom info, e.g. “Planting trees... (37%)”, or “Generating terrain mesh row 47 of 500”.

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).

Assuming there are no performance issues, it would be nice to tell Povray to select the pixels to render randomly, so that the image gets filled in gradually instead of from top to bottom and from left to right.

Also, maybe an option to tell it to render every Nth pixel.

Request an #ELSEIF statement in POV SDL.

Request #BREAK statement inside #WHILE and #FOR loops.

Many programming languages support an indeterminate number of parameters in functions/macros.

JavaScript for instance supports an “arguments” object.

Lua for instance supports the “args” object.

I would like to see that added to POV as well.

Here’s an JavaScript example:

function ArgTest(a, b){
   var i, s = "The ArgTest function expected ";
   var numargs = arguments.length;     //Get number of arguments passed.
   var expargs = ArgTest.length;       //Get number of arguments expected.
   if (expargs < 2)
      s += expargs + " argument. ";
   else
      s += expargs + " arguments. ";
   if (numargs < 2)
      s += numargs + " was passed.";
   else
      s += numargs + " were passed.";
   s += "\n\n"
   for (i =0 ; i < numargs; i++){      //Get argument contents.
   s += "  Arg " + i + " = " + arguments[i] + "\n";
   }
   return(s);                          //Return list of arguments.
}