Hi (again),

This question is quite important for me because it would mean that Houdini is truly different from the other packages (and that's what I'm looking for )

Imagine, you have a wall and windows randomly copying on the wall. Is it possible for example to decrease the diffuse value of the shader affecting the wall around the windows ? In other words affecting a shader accordingly to its distance between an other object .


Thanks in advance
Julien

I don't believe you would manage this at rendering time alone - I don't think any package could do that. However, it's fairly trivial to do this by creating an attribute in geometry and passing it to your shader. In other words, work out in Houdini a way to measure the distance between two objects, then massage and pass that as an attribute(typically using the AttributeCreate SOP). This would mean that each point would have an attribute, say “nearness”, that you could grab as it comes into your shader(Parameter VOP) and multiply the diffuse by it.

There's a tutorial movie that describes in more detail about passing attributes but alas I can't remember which one - perhaps someone from SESI can point you to it…

Hope this helps a little,

J.C.

Hi.
If you want to apply the same shader where parameters change on a per-copy basis, have a look
at this video tutorial:

http://www.vislab.usyd.edu.au/sidefx/houdini_video/by_topic/rendering/index.html [vislab.usyd.edu.au]

name: geometry instancing.

It's a recent feature
It's not fully explained, (i found some informations only in this video) so you'll have to watch it with attention). :roll:
It makes Houdini truly different from other packages ( as many other things).
(only works with houdini 6)

Hope that helps!
(at least, give you new ideas) :!: