[JPMays]

i've searched the forum for a while now but haven't found an answer that explicitly applies to my problem. I am trying to model a rock wall , but the displacement does not wrap around the corners. Here's my first attempt (sorry for the low res).



After some searching I found a suggestion to fillet the edges of my object (the original was just a polysurface block).



And this is what i get upon render:



The vertical edges seem ok, and the short top edge, but what's going on with the long top edge? What can i do to fix this?

BTW, my block is 2' x 2' x 10', w/ a 2" radius fillet, and I have Box projection selected under Rhino texture mapping.

Thanks!

[JPMays]

Ok, after checking it out in Rhino render mode, I can see what's causing the black stripe, but still don't know what to do about it. Also getting solid divisions between edges.

[JDHill]

That is a classic example of what happens in Rhino when you map an organic object with a cubic mapping - you are seeing, at the middle of the fillet, where the mapping switches from one face of the mapping box to the other. You would want to use a Surface mapping here - that precludes the Real Scale feature, as it is inherently a cubic mapping.

[JPMays]

Ok, I switched to Surface mapping, which then bumped up the scale, so under the Maxwell Object properties I changed the x value to .5, which pretty much matches what I had before. However, i get a similar effect.



Haven't tried to render yet though, displacement is such a memory hog.

[JDHill]

That's still a cubic mapping - make sure Real Scale is disabled in your Maxwell textures, then switch the object to use Surface mapping in Object Properties > Texture Mapping. If it's already on Surface mapping, switch it to something else, then back (it's a Rhino thing - you need to change something in order to get your viewport updated).

displacement is such a memory hog.

Have you measured this? Because in Maxwell, displacement takes virtually no memory at all; it's all done on-the-fly with pure math (read: you pay in GHz rather than GB).

[JPMays]

Ok, did as you suggested. I seem to have taken a step backwards though, because it looks worse than before, and it seems the displacement is not working as well as it was either. The texture is also really pixelated; is that because the scale is off? How do I change the scale if I disable Real Scale and use Surface projection? The fillets are hugely obvious.

[JDHill]

How do I change the scale if I disable Real Scale and use Surface projection?

To change the texture size for a Surface mapping, you would want to use the Tile X/Y parameters in the plugin's texture editor.

Even so, you are not going to get a very good result - as you can see, Rhino's Surface mapping is going to leave much to be desired, as it will map each surface in the polysurface independently. The only somewhat-acceptable option here is to use a camera-oriented Planar mapping; Rhino has no such mapping, but a script for generating one was posted here: http://www.maxwellrender.com/forum/view ... ar#p284599

[JPMays]

I can try all that, but you don't seem to optimistic that I will get a good result. Is there another way to get what I want? A different way to construct the object or something?

[JDHill]

Well, with this particular object (filleted cube), texture mapping in Rhino is always going to be somewhat lackluster; for other objects, that may be the case to a lesser or greater extent, it just depends on the object in question. As far as it goes, yes, there may be different methods of construction which lend themselves to better mapping, but those are all very object-specific. The camera-mapping trick (takes two seconds to try - just copy the macro, select the object, go to the command line and hit paste, then hit enter) can give you something that works relatively well, but in the end, if you simply can't get what you're going for in Rhino, you just end up needing to use another software that has more comprehensive UV mapping tools.

[Frances]

JP, in situations like this with Rhino, I alway pray that my stone wall will have another object as a cap. In that case, I construct a profile curve and extrude it. The result is a single surface and Surface texture mapping mode is tileable in that case, plus the corners displace nicely.

Something to try if your wall doesn't have a capstone, is to create your box, fillet the edges, and explode the box. Then reparameterize your surfaces and apply surface texture mapping (it should be tileable if you reparam.). Get all the edges to the same scale appearance (this is tedious), then mesh them. Attach the meshes together and weld the vertices at the seams. The surface mapping will carry over to the mesh and be maintained when you join them.

[JPMays]

How do I reparameterize? I've adjusted my object so I am now working on a truncated cone, which should be simpler to accomplish.



I'm also having an interesting problem with blocks/instances and displacement. You can see in the image the difference between the two objects: they're the same surface, only the one on the left is in a block. Why does the displacement not work? I can live without it being blocked in my model, it's only repeated 6 times, but i thought that would help for it to be exported as an instance.

[JPMays]

-double post-

[JPMays]

The only somewhat-acceptable option here is to use a camera-oriented Planar mapping; Rhino has no such mapping, but a script for generating one was posted here: http://www.maxwellrender.com/forum/view ... ar#p284599

I tried this with my earlier object, and it seemed to work well. I will try it on the truncated cone. Will this work with blocks?

[JDHill]

The displacement won't work, it's not supported on instances. You may run into some Rhino issues with mappings vs. blocks too; if I remember correctly, there are still some basic problems there.