Zbrush to Vray for Maya - 32 Bit Displacement

[henning]

Hello lovely people,

For as long as I can remember, I’ve struggled with displacement maps. Getting them out of ZBrush and setting them up in a render engine has been a mystery to me for ages. Over the last couple of days I’ve been doing some serious research into it, and I’ve written a tutorial which explains the most efficient way I’ve found of setting up a displacement map in Vray for Maya where you get as close as possible to your ZBrush sculpt with as little effort as possible.

If you have any comments, critique or suggestions, I’m all ears.

Here you can find the link to the tutorial.
http://henningsanden.com/2011/12/03/zbrush-video-tutorials/

ZBrush sculpt

Vray render

Attachments

[testudinis]

wow, awesome tutorial! just what i needed, thanks a lot!
also really nice sculpt!

[henning]

Thanks!

Another tutorial.

Reprojecting Details in ZBrush
http://henningsanden.com/2013/03/06/reprojecting-details-in-zbrush/

[system]

Hi,

First off… thanks for taking the time to write that tutorial in such a clear and amusing way.

I just did an experiment this morning on a wooden beam I’ve been sculpting for a personal project and I’ve come across a few things that I thought might be worth looking into.

1. The vrayDisplacement node

In your tutorial you attach the displacement texture to the appropriate slot in the shading group. Instead, if you add the vrayDisplacement node to your object (create>V-Ray>V-Ray displacement>Apply Single vrayDisplacement node to selection), and attach the file texture here, you’ll have a lot more control. If you decide to create some auxiliary passes for your scene later on (mattes, lights, etc), you won’t have to make sure your other shaders also have the displacement associated with them. TLDR, The vrayDisplacement node essentially makes the displacement associated with the object instead of the shader, which is nice for lighting TDs

2. Allow Negative Colors

I found that I absolutely had to enable this option in the file texture node for my displacement (Attributes>VRay>Allow Negative Colors) or I would have large regions that looked clipped or undisplaced. Maybe I did a lot of cutting away instead of building up in zbrush and that’s why it made such a dramatic difference? Worth Checking out…

3. TIFF vs EXR

I couldn’t tell the difference, and maybe this was a problem in older versions of V-Ray, but there used to be an issue where TIFFs rendered strangely and it was recommended to bring your displacement map you exported from zbrush(32-bit of course) into nuke, shuffle the red channel into RGBA, and then re-export it back out as an .exr. Apparently .exrs play nicer with V-RAY. I was just wondering if you had run into anything like this.

You can see the thread here if you have a login at chaos group:

http://www.chaosgroup.com/forums/vbulletin/showthread.php?52699-zbrush-to-Vray/page2&highlight=Zbrush+displacement

4. Seams

I’ve been having issues with UV seams after displacing and I’m not sure if it’s just because they’re usually in areas with sharp transitions ( i.e 90 degrees) or I did something wrong when I exported the map. My UVs are more or less perfect ( I use Headus UVLayout ). I don’t use smooth UVs typically, upon exporting or when smoothing in Maya. Anyway, if you’ve run into anything like this I’d love to hear your experience.

I think that’s all I can think of at the moment. Thanks again for the tutorial(s)!

-f

[dasnico]

thank you for the tutorial.

could you be kind enough to tell me when i should unwrap the model? when its still in a low poly state or high poly? or it doesn;t matter? thank you

[henning]

Dasnico: Thanks!

Well, it depends to be honest. In a production you should probably UV map it right away so that you can sculpt while the texture artist is working side by side. For personal projects though, I prefer to UV map it once the sculpting is done. When you sculpt, you do alter the base mesh, which means that if you UV map the mesh which hasnt been sculpted, the UVs might not match properly with the sculpted mesh. I’m honestly not sure if the changes will be big enough to notice though, but as a general rule, I UV map as late in the game as I can.

Oh, and another tutorial! This time on how to use Modo and ZBrush together

ZBrush to modo - 32 Bit Displacement

[henning]

Aaaand another one: How to UV map efficiently with UV Master.
http://henningsanden.com/2013/04/13/extremely-efficient-uv-mapping-using-zbrush/

[henning]

Another tutorial is up! I hope you guys like it.

How to make a turntable for presentation in ZBrush.