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Fur shader

Posted: Sun Apr 29, 2007 6:21 am
by Virion

Posted: Sun Apr 29, 2007 10:15 am
by vermeer
Quite interesting. there was already some experiment done here by someone... (sio? can't remember...)

I'd love to see th epoint where hardware and programming techs evolve as much as for the artist with some sort of parameters, even in an ini, text file, could do a no hair character, making just the growing area of head tagged polygons, and asigning in the text files some properties like physic properties, lenght, etc...Like it's done in shag hair, or most recent Max or blender... (blender I think a bit yet to soon, but is getting near to have a solid hair system... )

Posted: Sun Apr 29, 2007 10:46 am
by sio2
There's a few fur demos on my site. I was going to add another one using a texture to specify tangent-space fur length, so you don't have fur on your face, etc. Haven't had time to do it yet, though.

Posted: Sun Apr 29, 2007 12:59 pm
by Virion
sio2 wrote:There's a few fur demos on my site. I was going to add another one using a texture to specify tangent-space fur length, so you don't have fur on your face, etc. Haven't had time to do it yet, though.
Waiting for the demo... 8)

Posted: Sun Apr 29, 2007 3:17 pm
by omaremad
I made a postprocessor fur shader which can take attributes from the artist which can describe it behaviour. Here is a small demo with source code, in this case its a whole scene with grass procedurally mapped onto the terrain, the colour and grass density are described by bitmaps.


http://www.megaupload.com/?d=R0MJ34WA

My postprocessor method can make the grass 'fully' programmable makinging it bend in any direction you want (for example y - direction to simulate attraction to light etc...) In the demo's case i programmed it to follow the contours of the terrain while growing slightly upwards, the grass also doesnt grow on steep slopes.

Other methods of grass/fur shading dont need shaders at all, they just use hand made shells with a dotty texture on them. The shell's can be genrated via a 'expanding' vertex shader but there is not much control on grass behaviour through vertex shaders. Also adding shells eats huge amounts of fill and transform rate which makes traditional methods not useful for terrains etc...

I also tried porting this method to blender via compositing nodes to replace belnders slow and memory consuming particle grass, however blender keeps removing the fine grass line through heavy antialiasing.