TheDunadan Posted August 11, 2004 Share Posted August 11, 2004 I was wondering if there is any way to easily get dynamic arrays into shaders to do something like the following: I want an shader to react with an particle system. Let's say I have a particle System and if an particle is close to the surface I want the surface to change it's color (e.g. some ramp mapped to the distance of P of the obect with the shader and the Particle Position). To make things a bit more tricky I'd want to change the color on those areas permanently. With a fixed # of particles the first part works all quite well, but I didn't menage to find a more dynamic solution to it. Thanks for any ideas Jens Quote Link to comment Share on other sites More sharing options...
Mario Marengo Posted August 11, 2004 Share Posted August 11, 2004 Hey Jens, Point clouds are your friends! I don't know if you're trying this in H7; but if you are, you could turn your particles into a point cloud, and then proximity tests are a breeze -- heck; you could turn each particle into a light source if you wanted to. As for the effect being persistent in time... you'd probably need your particles to stick and split again after the contact event. In other words, for persistence, you'd need the particles themselves to carry the "history" somehow. Cheers! Quote Link to comment Share on other sites More sharing options...
athomas Posted August 13, 2004 Share Posted August 13, 2004 Just thinking out loud, how about attaching attributes to your particles and then transferring these upon collision on to your surface and pulling this into your shader? Haven't tried it yet. andre Quote Link to comment Share on other sites More sharing options...
TheDunadan Posted August 13, 2004 Author Share Posted August 13, 2004 Thanks for your answers Thinking aloud is good Maybe I'm wrong, but for finer details/more prescion the geometry would need as well more detail to start with and I'd like to avoid that. Or is it possible to write/change textures at rendertime ? This would be pretty handy really to store collision info on the surfaces that way. Concerning the point clouds, are they already available in the H7 apprentice edition (H7.142 that is)? In the VEX help I couldn't find anything on them Jens Quote Link to comment Share on other sites More sharing options...
Mario Marengo Posted August 14, 2004 Share Posted August 14, 2004 Concerning the point clouds, are they already available in the H7 apprentice edition (H7.142 that is)? In the VEX help I couldn't find anything on them 13223[/snapback] Ahhhh; the apprentice edition. Mmmmnope... I don't think build 142 has all the stuff there. Sorry about that Oh crap; that means that apprentice people can't use the subsurface stuff either... Oh well; I guess it's a matter of waiting a bit. You'll love point clouds though; lot's of fun! Cheers! Quote Link to comment Share on other sites More sharing options...
AndrewVK Posted August 14, 2004 Share Posted August 14, 2004 Search system directs you to the old (6.1) VEX Reference. VEX 7.0 Reference located here: D:/Houdini 7.0/houdini/vex/html/quickref.html Quote Link to comment Share on other sites More sharing options...
TheDunadan Posted August 14, 2004 Author Share Posted August 14, 2004 Search system directs you to the old (6.1) VEX Reference.VEX 7.0 Reference located here: D:/Houdini 7.0/houdini/vex/html/quickref.html 13234[/snapback] Ah, thanks. In the 7.0 doc that comes with the Apprentice Edition, there isn't anything on the point clouds yet, but the VOP's are actually there in the VEX Builder. Btw. looking at the docs, I saw the new BRDF Shading Models Didn't see anything on raylabels or alike though, but maybe the final is in for a few surprises Jens Quote Link to comment Share on other sites More sharing options...
AndrewVK Posted August 14, 2004 Share Posted August 14, 2004 In the 7.0 doc that comes with the Apprentice Edition, there isn't anything on the point clouds yet H7.0.142 Win2k file:///D:/HOUDINI 7.0/houdini/vex/html/functions.html#pcloud or VEX Run Time Library Reference -> Runtime Image Acces Functions -> Point Cloud Texture Quote Link to comment Share on other sites More sharing options...
TheDunadan Posted August 14, 2004 Author Share Posted August 14, 2004 ...maybe I should order some glasses some time soon Quote Link to comment Share on other sites More sharing options...
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