Hello Alexandre, I tested a bit with cairo-gl.
see (dwarf model courtesy of psionic3d.co.uk) http://assimp.sourceforge.net/tmp/cairotest/sshot2.png http://assimp.sourceforge.net/tmp/cairotest/sshot1.png
As expected, drawing performance is *really* good, but running transformation & depth-sorting on the CPU is too lame. I'd therefore prefer using native OpenGL for a fluent 3D preview (the sample shown in the screens ran at ~10 fps on a moderately fast machine). But a separate render path using cairo-gl for testing purposes/experiments wouldn't be a problem. I guess a cairo preview would resemble the final image in Inkscape more closely, especially if inkscape moved to cairo :-)
Regards, Alex
PS: I'm not sure if my quoted mail below worked, at least I haven't received a copy yet.
Alexander Gessler schrieb:
Hey!
Since the project idea originally comes from me, I thought I'd chime in give a little perspective. We've been talking about completely moving to Cairo for quite a long time, and yet we've made just first steps towards that goal. This project could be an interesting playground for our expansion into the world of GPU accelerated rendering *and* it would help those of us who do technical drawing and deal with all sorts of 3D data.
Using a 2D graphics library to do the outsourced 3D preview seems a bit unusual to me, but why not - sounds interesting - The only consideration would be that while Cairo-gl will do the rendering very fast, the task of getting from 3- to 2D (aka transformation stuff & perspective projection) would be left to me and consequently be done without hw-acceleration. That's terribly expensive, so I doubt it will result in a fluently movable preview for meshes with more than a few ten-thousand polygons. But I have no numbers yet. I'll try it and report back.
It would be absolutely great if somebody wanted to be a potential mentor for this project idea ;-)
Bye, Alex
Side note: Assimp/Open Asset Import Library (for those who don't like the first name) is steering towards another stable release in late April.