Displacement Map Edge along Seems in 3DSmaxVray created in Zbrush

Klaus Hustle

Hi there,

i'm fiddling around with displacement-map creation out of Zbrush (to be displayed in 3DsMax 2016 and Vray) for a while now and i finally got very good results by following these steps: https://www.cggallery.com/tutorials/displacement/

It's a very good guidance for all the settings and stuff. Basically i created a simple object in Zbrush, detailed it a bit randomly just for testing-purpose, unwrapped UV's in 3DsMax and created the DisplMap under the rollout menue for displacement maps in Zbrush.

In 3DsMax i'm using the VrayDisplacementMod with a VrayHDRi shader for my displacement map (*.exr), some settings inthe displacement mod and it is really looking good for the first time ever! 

Now that i'm so close to perfection i've been a bit bugged about the visible edges from my UV's. It's pretty minor, but i want to improve it nonetheless, so I'm hoping you could give me some advise on that.

To make it as easy as possible i made a quick documentation of my settings and the problem itself.







I usually just doing some basic 3D modelling and rendering, but i want to step it up a little..next up is working with normals, if i get them to look as good as this i might switch completely, but for now my displacement-maps are looking way better..

Cheers!
 

sknueppel

Hey there,
good explanation of the problem
Could you maybe share a Picture of the displacement itself?
I would suggest these Issues are happening because of an edge padding set to zero. 

You could try to bhake it with xnormals (height map) and an edge padding of (lets say) 16 more or less depends on your Map Size.

Hope this helps ^^

Klaus Hustle

Hey!

yes, sure.. i saved the Displacement Map as *.exr file, but i did saved out a tif now, and it looks.. strange? never seen a height-map like this before. My earlier results with using Knald had the same issues, but the map looked pretty height-map'ish at least (from what i know).

These hard white borders look problematic, but i don't know how to get rid of them. I also don't know where i could change edge-padding in my current process, so i'm going to try xNormal later on, will see! 

Axi5

Yeah it looks like it could be a padding issue.

To show you some of the things that could go wrong with displacement and UVs:

1. Make a cube
2. UV it so each face is independent
3. Colour all faces black
4. Colour one face white and bake this out as a displacement map
5. Re-apply it.
6. Try again with soft edge normals
   

You should see that one of the faces splits off. Making sure that your displacement is consistent across seams is key to getting a good result. Depends on some renderer's interpretation though. (I'm looking at this from a realtime perspective, v-ray might calculate it's displacement differently).

Klaus Hustle

Axi5 said:

1. Try again with soft edge normals
   

You mean, re-arrange the angles of the normals on the edges? I don't know if i'm totally getting your point, but i think what you mean is what you get when you're not using the VrayDisplacementModifier in 3DsMax, you're getting these gaps between your sides.

Tried xNormal now, i'm getting even stranger results.. i don't know the software and there are dozens of things to set up, think i first have to wrap my head around the tool first Or might accept the results i have for now.. I would love to just experiment with the padding tho, but as mentioned, in my current workflow i don't seem to have the option to adjust padding at all.

Good call on experimenting with simpler arrangements first tho! 

sknueppel

I think the soft edge normals is a Maya thing. If so, I think you just have to set all faces in the same Smoothing group.

for just a test, use the script mentioned in this thread
http://polycount.com/discussion/48453/photoshop-padding

With it you can create a padding in Photoshop. I m not sure how accurate it is compared to a baker, but if the mesh looks better after it, it would be a hint that it realy is the padding, that is missing.

Axi5

Yeah it's a maya thing, I couldn't get my theory working with Arnold so I think it is definitely renderer specific

Klaus Hustle

sknueppel said:

I think the soft edge normals is a Maya thing. If so, I think you just have to set all faces in the same Smoothing group.

for just a test, use the script mentioned in this thread
http://polycount.com/discussion/48453/photoshop-padding

With it you can create a padding in Photoshop. I m not sure how accurate it is compared to a baker, but if the mesh looks better after it, it would be a hint that it realy is the padding, that is missing.

good idea, sadly i cannot run a script or alter the content of the *.EXR file i'm creating as the displacement map out of zrbush in any way. I need to find another way to create decent looking displacement maps to work with to try out the script, working on it, will see, maybe going back to knald for that.