Modular workflow question.

Gheromo

Hello everyone,

I have stumbled upon an issue I never had to deal with before, so i'm not even sure how to search for the solution.

What I am trying to do: I have 2 pieces each on each side of the stairs sharing same UV space. However one on the left has small bit (2) that has its own UV space where I would like to put damage in.

Problem: Can anyone please explain what would be the workflow to sculpt in the details into this damaged part so that normal map would work well on a clean piece and damaged one in same time?

Here it is:

Gheromo

Heres the snapshot of the UV's. As I understand it will not work the way I planned simply because meshes are planned to have unique textures.

Gheromo

That makes sense. Would you mind telling me how would you approach doing that?

When I started working on that I haven't really considered normal map issues that are potentially can arise, instead I was mainly focused on diffuse which can be painted in fairly easy onto both models and make them look great. Which now makes me wonder is there even any point to try to sculpt into this piece, or do all normal maps from diffuse in PS with plugins like crazybump or ndo2.

m4dcow

Checkout this post by Kevin Johnstone:
http://www.polycount.com/forum/showpost.php?p=1505313
He has that railing texture done a modular way where certain damaged bits correspond to un-damaged bits and can put them together in a bunch of interesting ways.

That might be a bit complicated, so an easier method I have seen is what crytek does with alpha blended decals for damage.
http://freesdk.crydev.net/display/SDKDOC3/Using+Decals+for+Destroyed+Structures

Gheromo

Sorry for not being clear, my main thought is to keep it all in one texture file to save memory that can be crucial but in same time I want to break up repetition.

Here is what I've got. I have duplicated vertex normal's from clean piece onto a broken one. So that shading looks exactly the same.


I keep thinking to sculpt into broken side, then bake it. So if I do it carefully normal map will not change much for the clean piece and I will be able to finalize it with some cloning in PS.

however having a separate material for a broken piece with a tilable texture seems like a very quick solution that doesnt require all this painful process.

Seems like process I keep thinking of is too much time consuming to do it to a point so it looks good.

Gheromo

@m4dcow

Decals method seems like an interesting solution I might try out.

Gheromo

I have to admit this is really out of my comfort zone what I am trying to do, problem is I don't quite understand the process I have to go through exactly in order to match normals on a clean piece and broken uv island.

Do I sculpt in clean piece first to a finished state, then bake it in to get normals. When that is done its only the broken piece itself that is left, which I cant figure out how to do in order not to mess up normals for the clean piece yet make the broken piece look like its a part of the structure and not have a seam like you get if you would put another material on that area. I hope it makes more sense. This is exactly what I am trying to get help with.

Scruples

You should really use the decals method.

To do it the way you are trying to you have to...
•Finish modeling the highpoly of the undamaged piece
•Make sure the vertex normals on both models are identical on every piece that uses the same texture space.
•Have hard edges on all UV borders
•Polygroup by UV's
•Transfer the sculpt via projection of the finished undamaged piece to the damaged, but only to the parts using the same UV space by masking the damaged polygroup.
•Mask the undamaged parts and continue to sculpt the damaged area
•Export, bake

I am sure there are variations to this but I can't think of any as accurate, compare with decals method which is only a couple steps.

tristamus

Am I missing something here, or is this more complicated than it really needs to be?

Why don't you just give that section (The damaged part) it's own bit of UV space above the unbroken one, so that when you bake down your high poly, it'll have that normal info?

Scruples

He wants the undamaged parts to occupy the same UV space while still avoiding an obvious texture/material seam.

Ged

tristamus wrote: »

Am I missing something here, or is this more complicated than it really needs to be?

Why don't you just give that section (The damaged part) it's own bit of UV space above the unbroken one, so that when you bake down your high poly, it'll have that normal info?

this seems the most logical solution, why go to such extreme lengths just to save a little uv space?

Gheromo

Okay I think easiest ways to do this is, to put both pieces in same place on 0,0,0 axis and sculpt in the clean piece, and then make a layer in zbrush and sculpt in damage details over. As a result I will be able to see where damaged part is and will make it easier to control the process. By doing that I will avoid having need in a decal and an alpha texture too. Seems easy. sometimes I wonder if I over think stuff when I am working... :poly142:

MisterSande

Gheromo, some pictures would help to understand why you chose your method xD

Gheromo

Before I will make any bold statements that it worked or whatever. I will do a test run quickly and will post reply in a bit and show what exactly I did. Either way will it work or not.

Gheromo

Worked.
What I did:
imported both pieces.
sculpted over clean piece.
unhide broken piece to see the boundaries where I made it broken.
Created layer on a sculpted piece and sculpt into the broken piece.
bake plus a bit of photoshop work to get broken UV shell into clean bake texture.

p.s. ignore doodle sculpt