Neutralize Vray Displacement Property

[jujubee]

I've been making grass out of a plane using Vray displacement. Let's say I want to add a garden section that's not displaced. I can cut out a section of the plane and apply a new undisplaced material. That would work. But it's a little pain sometimes.

I'm wondering if it would helpful/possible if there was a material or object setting that could 'turn off' displacement where another object intersects.

For instance - lets see you had a head of a furry mouse. You could take a couple spheres for the eyes and check 'displacement intersection' under properties rollout for those spheres. This would prevent fur from intersecting the eyes when/if the mesh intersects.

[DaForce]

I dont think it would work.

Could possibly be done via scripting, have a script that tracks the position of each object and if they intersect it then affects a black and white mask material which is then used to mix with the displacement material.
So in your case where the eye sphere would intersect the rats head there would be a black spot on the mask map which would indicate no displacement to take place.

But having script to work out the volume of each object and track that.. might be a fairly complex task.

Of course you could just PS up a proper displacement map in the first place

[ralf_al]

If it ever arrives this could possibly (at least partially) be done by using vray 1.5s occlusion map.

Using an occlusion map as a mask for the displacement map might work at least in some cases

[vlado]

Using an occlusion map as a mask for the displacement map might work at least in some cases

This can never work. The reason is that you get an infinite cycle - to calculate displaced geometry, you need to calculate the occlusion, but to calculate the occlusion, you need to intersect rays with the displaced geometry, but then you need the occlusion again... and so on. Kind of like which is first, the hen or the egg...

Best regadrs,
Vlado

[ralf_al]

This can never work. The reason is that you get an infinite cycle - to calculate displaced geometry, you need to calculate the occlusion, but to calculate the occlusion, you need to intersect rays with the displaced geometry, but then you need the occlusion again... and so on. Kind of like which is first, the hen or the egg...

Best regadrs,
Vlado

Too sad, but seems logical.

What about an additional option to calculate the occlusion map without the displacement active? In many cases, where the displacement is used just for enhancing the microstructure of an object (e.g. grass or skin) one wouldn´t necessarily need the displacment included in the occlusion calculation. Of course this wouldn´t work for entire mountains modeled with displacement maps.

[vlado]

Too sad, but seems logical.

What about an additional option to calculate the occlusion map without the displacement active? In many cases, where the displacement is used just for enhancing the microstructure of an object (e.g. grass or skin) one wouldn´t necessarily need the displacment included in the occlusion calculation. Of course this wouldn´t work for entire mountains modeled with displacement maps.

Well, you can bake the occlusion map with the undisplaced geometry and use this later on.

Best regards,
Vlado

[ralf_al]

Well, you can bake the occlusion map with the undisplaced geometry and use this later on.

Best regards,
Vlado

Of course, but as a friend of one click solutions that don´t require any additional work by me, I somehow would really like the proposed optional checkbox...