Generating a Displacement Directly from Voxels

[ekunzendorf]

Hello All!

This is probably a REALLY dumb question. But... I have a voxel model and a retopo'd mesh. I want to bake a displacement map from the voxel mesh and take it into Maya and render it in mental ray. Is there some trick to doing this?

I am having a lot of trouble trying to get this to work. Specific questions include:

Do I need to convert the Voxel model to mesh by quadrangulating?

Scan depth is based on brush units, so if the voxels only project a small distance a way from the mesh (or dip under it a little) I can decrease the scan units from the default? Is there any problem with having larger scan units?

For Maya, which sees black as 0 level, which Displacement Type should I use?

Anyone know what Approximation Editor settings work best?

Thanks and have a great one!

Excelsior!

Eric Kunzendorf

Jacksonville University

[philnolan3d]

Simply merge your retopo mesh to the painting room in micro-vertex mode, that's under the Retopo menu in the Retopo room. It will displace the mesh, then you can export that displacement map from the Textures > Export menu.

To answer another question, quadrangulation is not converting the voxels, it's just doing automatic retopo. You said you already did retopo so no you don't need to do that. BTW if you're seeing "Quadrangulation" in the menus then you're using an old version of 3D-Coat. The latest is 3.5.03 you can download it here:

http://www.3d-coat.com/forum/index.php?showtopic=6634

I don't know much about maya so I don't think I can help with anything there.

[Javis]

For Maya, which sees black as 0 level, which Displacement Type should I use?

It's been a while since I've used Maya, but you can do:

16bit (for sure)

Zero level black, Not normalized (pretty sure on this normalizing setting, but admittedly can't recall exactly)

If it's a SubD object make sure you tick on: "Coarse mesh"

[ekunzendorf]

Thanks for the replies!

So from what I understand, there is no way to generate a displacement directly from the voxel model. Is that correct?

And yes, Phil, I am working on 3.3. That is what we have in the lab because that is what we started the term with. I don't upgrade in the middle of a term. It causes A LOT of problems with instruction. I'll upgrade during our winter break. I'm looking forward to it!

Update on what I'm finding. I took my Retopo mesh, which, interestingly enough, I had already merged for PPP and painted on it with color and depth. When I then merged for MV sculpting, the color carried over and the depth that I painted also displaced the mesh! This is pretty cool, but I didn't expect it. All I really wanted was the bumpy-ness of the smooth voxel model to carry forward.

Okay, so I hid all the paint layers and just merged for MV and it worked! Now I just have to get my settings right in Maya. The displacement is displacing too much, I'll figure it out!

Thanks again!

Excelsior!

Eric Kunzendorf

[Psmith]

Eric:

And, when you do get it all figured out, I wonder if you would mind posting a short, step by step process of what you were trying to accomplish and what steps you took to get there. Especially needed is why you chose this "route" in the first place. This would be most helpful for everyone.

Thanks,

Greg Smith

[Javis]

Thanks for the replies!

So from what I understand, there is no way to generate a displacement directly from the voxel model. Is that correct?

Ahh, if you've already got a retopo mesh and you are already generating a normal map, you can generate a displacement map, too. Sorry, for some reason I thought that was answered. 3DC thinks of normal and displacement in the form of just "depth" (well, sort of, but let's keep it simple!). If you've already generated a normal map by merging to the paint room from the Retopo room, then:

Go to:

Textures>Export>(Choose a displacement option)

And 3DC will generate a displacement map based on the depth the same as it would a normal map. I've used this method for a presentation at GDC and in projects (clients and personal) and it works pretty well. Hope this helps.

[michalis]

Okay, so I hid all the paint layers and just merged for MV

I really don't understand.