gameblender vector output ( GL2PS )

Game Engine Game Engine Support and Discussion
1

Hi there,

from time to time I need 2D vector output from a 3D modell, so I can easily use it for postprocessing and compositing in programmes like Illustrator or Inkscape.

Basically what I need is a clean vector rendering, which I can take apart, edit and recompose in some way. Vector format is also helpful because it is easily scaleable.

Here are two examples for possible uses:
http://www.realu.de/projects/spots/pics/drawings/051208-perspektive-A4-300.jpg
http://www.realu.de/download/MuseumX/img/060217_MuseumX.jpg

There is a library called GL2PS (http://www.geuz.org/gl2ps/), which can capture openGL commands into PS or PDF files.

Essentially it works by wrapping gl2psBeginPage and gl2psEndPage around the normal openGL rendering.

My idea is now that I could do the modelling in Blender, start the game engine, move the camera around, press a key and get a Postscript file.

Do you think it would be possible to integrate this as an option into Gameblender?

I had a look at the source and believe that a possible integration should go somewhere here: blender/source/gameengine/Rasterizer/RAS_OpenGLRasterizer ,
but I certainly could not do It myself, since I don’t understand enough of blender source/ opengl/ c programming.

Maybe vector capturing could be enabled and disabled from python with something like GameLogic.Rasterizer.enableCapture(filename=’…’, …)?

Does anybody know if this makes any sense?

All the best,
Stefan

2

interesting.
in the unlikely case I got extra spare time, I might want to check this out.

Otherwise, perhaps Charlie/snailrose, Lagan or Dreamkatana has time?

Erwin

3

Hi Erwin and everybody else,

today i made some quick hacks and compiled gl2ps into blender.
To my great surprise it actually worked.

I can render shaded SVG versions of our favourite monkey.

For the time beeing, all the parameters are hardcoded into
the source, rather than being accessable from python, but still
i am quite happy with the result.

I hope i can do some further work on this on the weekend or so.

best,
Stefan

4

Hey,
Well it looks like you have everything in place already, but I gave it a shot.
In my opinion this should be an option in blender, like here
http://projects.blender.org/pipermail/bf-committers/2006-February/013687.html

But it’s neat anyway.
Here are three pictures made from the game engine…
http://home.bresnan.net/~snailrose/shots/

and a build here.
http://www.continuousphysics.com/ftp/pub/test/index.php?dir=blender/&file=GL2PS_Build.zip


from Rasterizer import *

# types ... 
GL2PS_PS  =0
GL2PS_EPS =1
GL2PS_TEX =2
GL2PS_PDF =3
GL2PS_SVG =4
GL2PS_PGF =5

# flags ...
GL2PS_NONE                 =0
GL2PS_DRAW_BACKGROUND      =1
GL2PS_SIMPLE_LINE_OFFSET   =2
GL2PS_SILENT               =4
GL2PS_BEST_ROOT            =8
GL2PS_OCCLUSION_CULL       =16
GL2PS_NO_TEXT              =32
GL2PS_LANDSCAPE            =64
GL2PS_NO_PS3_SHADING       =128
GL2PS_NO_PIXMAP            =256
GL2PS_USE_CURRENT_VIEWPORT =512
GL2PS_COMPRESS             =1024
GL2PS_NO_BLENDING          =2048
GL2PS_TIGHT_BOUNDING_BOX   =4096


type = GL2PS_PDF
flag = GL2PS_DRAW_BACKGROUND+GL2PS_OCCLUSION_CULL+GL2PS_BEST_ROOT+GL2PS_SILENT

GL2PS_Shot('test.pdf', type, flag)

Thanks,
snailrose

5

Wow, thanks,

impressive …

That would be too cool to see that in a Blender release.

I’m everyday more impressed by Blender.

Thanks,
Stefan

6

that’s insane I’m waiting for it from the begining of my work with blender game engine.

pleasse try to put it into next release of Blender.

thx jm

7

Nice!

In “Blendo.pdf” I see textures or not? How do I do this, I tested a quite complex file but there were no textures at all.

Regards,
Carsten