Surface Splatting Rendering Using Geometry Shader

[Sakanakao]

I like the application of a depth of field effect on that checkerboard. Pretty neat way to do it.

[Bleenderhead]

So, it can render really detailed structures more quickly using this technique than with polygons?

[dlmtavar]

Well, theoretically, the final result is the same for both rendering techniques. Surface splatting use a point based primitive called surfel. Datasets that was created using this primitive dont have topology information, but it can be renderized using surface splatting in real-time. So, if you have polygonal datasets, traditional rendering methods are easier and faster than surface splatting.

[Kinekun]

Pretty interesting and good hands-on approach to functions of geometry shaders. Adding some music or comments would make it an even better video

[1337H0E]

thanks. I didnt know about this format. Through my work Im dealing with laserscans, and in arbitrary point clouds its quite a challenge to compute normals, but for trying stuff it comes handy if you have get all the data at once ;)

@pasovec: Thats a very straight forward approach. But i think it can only handle specific cases. Plane fitting would be more accurate, but also quite expensive as far as i know.

[dlmtavar]

I am using the Pointshop3D sfl files. This files format have all that you need to make point render using surface splatting. There are positions, normals, colors and radius of surfels primitives. If you need a more simple file format you could try use the sfl2ascii conversor.

[1337H0E]

looks really nice :)

do you get the points from a range scanner ? and if yes where do you get your normals from?

[pasovec]

Normals could be computed. You find... lets say 10 nearest points... compute vectors and averege them. It works quite good ;-)

[codeblocks]

Hey, I use surfels for my LOD system. rulez!! openGL?

[dlmtavar]

Cool! OpenGL and geometry shader. It's very fast...

[codeblocks]

In my case and for speedup a bit, I use some kind of group backface (store surfels in one of the six vertex buffer given their normal).

Are you painting dots? (like "GL_POINTS" in GS), I saw that some of your surfels are rotated!

[dlmtavar]

Yes, for each GL_POINT passed through the opengl pipeline a 'surfel' is

created in geometry shader (with position, radius, normal and color).

I am used a texture mapping with alpha blending to make an EWA

resampling filter approximation.

[codeblocks]

Interesting. thanks for answer, in next days I need to read more papers about EWA splatting for my job.

Cool stuff

[joshig1983]

How many polygons were in the face near the beginning? It looks like several hundred thousand.

[dlmtavar]

No,there are 40880 Surfels in the face, not polygons.

[PaulinhosmBR]

it looks very good

congratulations!

[dlmtavar]

thank you!