Soma Yukihira Model Progression & Issues

I've been hard at work trying to finished this little project this weekend, and all was going well, at least in ZBrush. Here is my current progress. It is more or less finished, but there are some serious problems when it came to exporting the polypaint textures for Maya...

The green parts are parts that share UV space with their opposite counterpart, and thus do not require texturing. I coloured them green to make sure that I remembered this when it came to exporting, in attempt to avoid unwanted artefacts.

So here is an example of an issue that I've found all over the model when exporting the textures:

Apron Mesh as seen on the front of the Soma Yukihira model above.

On the left, you can see the direct result of going through the usual paces to export the polypaint as a texture map. On the right is the result that I expected, where the texture fills the entire UV space provided for the mesh. This annoyed the hell out of me when it was happening, but I soon found out why.

The following image shows 2 meshes. The left one is the one that I had worked on, The right one was the new mesh created to fix the problem.

Morph UVs button

Apron Mesh inside ZBrush with Morph UVs applied.

Using the 'Morph UVs' button in ZBrush, this clearly showed me that the original mesh had had its UVs smoothed while subdividing the mesh; something that surely no one would want to have happen...

Evil Smooth UVs!

The check-box that caused all this mess is here in the Geometry tab, called 'Suv', for 'Smooth UVs'. Is must be disabled when adding subdivisions to the mesh. Now I must go back through my model, creating a new mesh above each current mesh, subdivide it with this button unchecked, and then project the original detail to them. It has to be done this way, as simply updating the mesh will automatically subdivide again with this option still checked...

Xiahou Ba Polypainting Clean-up & Detailing - Polypaint Artefacts

Now that Xiahou Ba has his final 'in-game' meshes with the high resolution sculpt and paint information projected down to them, I have started giving him any finishing touches he needs. in the process however, I have ran into a problem regarding Polypainting and the use of Layers in ZBrush.

I have fixed this issue now, but thought I had better post it here to show how to fix the issue for any fellow Googlers.

The top image shows the issue at hand; there are artefacts where I have tried to paint over already-existing paint. The paint can be hidden but only when using 100% pressure over it, which obviously is not what is wanted.

• The problem occurs because of the use of layers.
• When you make a new layer, it will say REC to the right of the layer, signifying it is now recording what you do to your sculpture to add it to that layer. When you are done or want to change layer, you click the REC symbol to make it close the layer.
• If you later decide you need to add more detail to an existing layer, this is where the problem occurs. Trying to paint over data that has already been laid out on that layer will cause artefacts because essentially there is an internal alpha map ZBrush is using to sort the layers of colour as efficiently as possible. This 'internal alpha map' is set up when the layer is closed, and only full pressure can add to it later.
• To fix the issue you can do one of two things:
• Bake all current layers down and don't use layers much if at all when polypainting.
• Or the better option; if you decide you need to add something else to an existing layer, make a new layer above the current one, adding your detail on here instead. Once you're finished, simply merge this new layer down with the one that you want the detail added to. Its a bit of a strange thing to have to do, but that's how it is for now at least.