Different material on same object, displacement map

dear rhino-forum!

here is what i want to achieve: i try to design a stone sculpture with different surface finishings. the idea is when i cut the block with a parallel projected curve (boolean difference) i want the resulting surface to be polished and the remaining part of the stone block to appear somewhat “natural”, therefore I decided to use a displacement map.

i already searched the web for a solution of using different materials for one object in rhino (like it is possible in 3ds max with the numbering of the object’s faces) and found out that it was only possible when the object is exploded.
that might be a solution for let’s say differently colored faces… but when I have a “normal” and a displaced material there appears a gap between these faces. (which is not surprising but really annoying as I don’t want to fake the edges in photoshop)

is there any solution to that in rhino 5?


I think you will get the problem also if you use different materials at different sides, could be you need an other solution.

Couldn’t you not apply a Rhino geometry displacement first and than cut the object?

hm… it seems like we’re maybe not really talking about the same thing…

i’m talking about rendering (with vray) and that rhino is not able to relate the faces of my object anymore after exploding … so that the render engine would know that i would like to connect the different faces

the edge problem

3ds max

I understand. I mean you could create a natural looking stone per Rhino object displacement first and cut them. So you wouldn’t need Vray displacement anymore. Looks like the easiest solution.
I would use a low res Rhino displacement and add a Vray bump mapping where needed, because displacement is visible for the large deformations only. For the small details bump mapping is good enough.

A Vray-only solution could be difficult.

alright. this way i could have the cut object as rough as the original one. but then i cannot specify the cut surface to look smooth and glossy. or at least i don’t know a way to achieve that =/

I would create a stone with displacement and cut them. Than I would extract the polished plane (_extract surface or if your work with meshes _extractmeshpart) and assign the material, for the other part I would use the bumpy stone material.