ZBrushCentral

Polypaint layers independent from displacement layers?

ZBrush Usage Questions
#1

I’ve been sculpting details onto a character mesh and I have used layers to separate different layers of detail all with the intention of creating a displacement map for export.

I plan to create finer details such as skin pores as a bump map in poly paint and want to use layers during this process too.

How, if indeed possible, do I create rgb layers that are independent of the displacement layers? I have turned off zadd and turned on rgb ready to paint my bump map but the displacement layer list under ‘Tools’ hasn’t changed which seems a little counter intuitive.

Can anyone suggest a workflow that will give me a separate set of polypaint layers and separate set of displacement layers to work on?

Thanks

#2

Layers can contain sculpting and/or polypaint, so if you only want to paint simply turn off ZAdd and turn on RGB. Make sure that your model is filled with color before turning on layer recording and also don’t paint with materials (make sure RGB is on not MRGB) as that can cause problems. You can tell the contents of a layer by holding the cursor over it in the list - the pop-up will show Shape, Polypaint and Target Mask with (Empty) beside those that are unused.

One thing to note though is that you won’t get any more detail by polypainting a bump map as you would by actually sculpting the high resolution detail. This is because polypaint relies on the polygon density in just the same way as sculpting. So you could simply create your bump map by generating a displacement map from the second-to-highest subdivision level.

#3

Thanks for replying (again!) Marcus,

That all makes sense.

Its interesting what you say about the bump detail. I was hoping to paint the skin pores as a bump map for rendering in Modo.
I have found that this level of detail has never really carried across from what I sculpted if I use a displacement map and assumed that it was either the map size or something else that was preventing Modo from replicating the fine details that I had sculpted in ZB.

By using a bump map I hoped that I could use a large size map but its greyscale properties would be less of a burden on the rendering in Modo.

Do you have any suggestions or advice to retain that level of detail once in Modo?

#4

I’m afraid I don’t know Modo. But if you are rendering displacement then there are basically two things that affect the amount of detail you can get:

a) The size of the map. As you say, the larger the map the more detail it will hold. Roughly speaking a 4K map will be able to hold the detail from a 10 million polygon model - but this will vary depending on your UVs.

b) The render-time subdivision in the app you’re rendering in. In order to displace the low resolution model accurately the renderer has to subdivide each polygon, so that each pixel on the map has a corresponding point that is displaced. It may be that Modo calculates this value based on map size or you may be able to set a value.

If either of these things is not at the optimum then the renderer has to interpolate between values which will lead to loss of detail.

#5

Thanks for that Marcus

I am experimenting with an 8K map which does lead to better levels of detail but I still think Modo has room for improvement somewhere in its replicating the ‘look’ that I have in ZBrush.
Perhaps there is a cut off point because at the end of the day they are simply two different programs.