How to creating a displacement map for a LowPoly model from a HighPoly subtool (in zBrush)?

3DShaq

Hi,

I'm currently working on a character, currently the head and neck. I'm at the point where I have a High poly subtool which has detail up to the skin. I know now that I need to create a displacement map for the lower poly version so that it's optimised for rendering

so I'v zmeshed the model into a lower poly and also unwrapped it, now how do I create a displacement map for the lower poly from the higher poly subtool? Do I need to divide the low poly and then project all, and then create displacement?

Thanks

cryrid

> Do I need to divide the low poly and then project all, and then create displacement?

If you're using zbrush to bake the map, then this is what you'll need to do. Other programs should let you use two completely different meshes as opposed to subdivision levels. 

3DShaq

When I create a displacement map, the file is completely black (mid value 0) or completely grey (mid value .5)  when I open it on File Explorer/Photoshop

kanga

Just to check: You uved a low poly version of your hipoly right. Your lowpoly (with the uvs) has been subdivided and at higher sub d levels has the ammount of detail you want from the disp map? Should be working. Go through a tute about making textures in ZB. Often there is some weird shuffeling with creating new textures.

3DShaq

Yh, so I imported the LowPoly (unwrapped) and the HighPoly (not unwrapped) mesh into zbrush, then divided the LowPoly to a higher level, which I then projected to get the detail from the HighPoly.

So my intention now, is to create a displacement map from the higher subdiv level which I can apply to the lowest subdiv level.



I'm following this tutorial on how to make a displacement map: https://www.youtube.com/watch?v=CB4LxUpvep8 

Also: https://flippednormals.com/tutorial/zbrush-vray-maya-32-bit-displacement/

However, when I finish exporting the map and try to preview it in Photoshop, its just one solid colour with no other displacement information. 

Any idea what I could be doing wrong?

3DShaq

So I decided to try the Displacement Map tool in Tools and create displacement from that. It seems to have created the map and you can see the map where the mouse is hovering.

However, for some reason it's displacing the edges of each face as well?



I've also tried 'create and export map', but it does the same as before, and create a solid grey map; not like the preview of the map where the mouse is hovering

3DShaq

I think I've figured it out; as you can see, the tutorials ask to toggle 32bit ON, however when I turn it off, the Displacement Map information seems to show now:



Now there's this issue, there this strange stretching-like artefact...

cryrid

That error occurs when you have UV coordinates that touch or extend beyond the 0:1 space. When that happens, zbrush sort of wraps them over to the the other side. 

3DShaq

ah ok, let me check that

melviso

Currently, can u now bake between two different meshes in zbrush or u are still limited to subdivision levels?

cryrid

It still uses subdivision levels, as only one subtool is considered active at a time. 

melviso

@cryrid Ok. Thanks.