Displace in X/Y

[visualride]

As I understand displacement mapping, a mesh is created at render time that has it's points pushed or pulled perpendicular to it's face normals according to a luminance map.

I remember someone telling me a few years ago that the reason that Rendermans displacement was so much better than the competition was that its displacement could also displace in X and Y to the normal, allowing effects like scales on a dragon pulled over each other.

If this is not possible in VRay now, I would like to suggest a couple possible implimentation ideas for a kind of post displacement effect. I imagine grass having it's top verticies displaced in X/Y to the normal perhaps based on it's Z-height. Or perhaps a red-green intensity map describing how much to push/pull in these directions perpendiclar to the normal.

Perhaps this is coming out as just bable whilst I wait for a render, but it's interesting to think about.

[instinct]

Something similar is implemented in mr as 3d displacement. But it doesnt do any curvature, only displace the endpoints....so for example grass would still be perfectly straight, but at different angles.

Regards,
Thorsten

[joconnell]

That's what normal mapping does afaik.

[instinct]

well normal mapping only does better looking bumpmapping, but no displacement.

Thorsten

[DaForce]

Exactly, normal mapping doesnt affect the mesh surface, similar to how bump doesnt affect the mesh surface.

Vray ATM AFAIK (at the moment as far as i know.. lol ) doesnt have the sort of displacement your after. I would be willing to be it would be one of this features that is added after 1.5 is released as there isnt much call for it, just like my want for Volumetric caustics

[joconnell]

Sorry you're correct but normal mapping makes the correct red / green maps that can make surfaces go in more directions than just in and out. Shame about the displacement as you mentioned.

[visualride]

Thanks for the info joconnell. I didn't know that normal maps were so versatile. I'm looking forward to post 1.5 in displacement mapping. I can imagine uses popping up for well implemented extra control of displacement maps.

Hmmm, Volumetric caustics. I've seen those in the sky now and then. Kind of like caustics from a glass of water, but floating there. Aurora borealis effects? I can imagine a cool effect for some pixy critter in a movie with this effect.

[DaForce]

Kinda like this (render from XSI, not vray)


Basically you can see the caustics in fog..etc..

[visualride]

Whoa, cool effect! How did you make this?

[DaForce]

haha sorry, i didnt make that... that render is from XSI.. i just wanted to demonstrate what volumetric caustics are like.