ZBrushCentral

Displacement in 3ds max 2009

ZBrush Usage Questions
#1

I’m attempting to get a displacement map from ZBrush 3.1 to 3ds max 2009, and I have a few questions.

I’ve been getting most of my information from:

ZBrush.info Docs “ZBrush to 3ds_Max - Generating a Displacement Map”
http://www.zbrush.info/docs/index.php/ZBrush_to_3ds_Max#Generating_a_Displacement_Map

and the thread “Rendering ZBrush Displacement-Maps In External Renderers”
http://www.zbrushcentral.com/zbc/showthread.php?t=20310

and a thread from aurick titled “Displacements: What is the difference between ADAPTIVE mode and DPSUBPIX?”
http://www.zbrushcentral.com/zbc/showthread.php?t=115

My ZTool at it’s highest subdivision level is 1,708,544 polys, and I’m trying to export a 4k map, so in Multi Displacement 3 I have my MaxMapSize set at 4096, and my DPSubPix set at 2. In 3ds max 2009, I’m using a SSS Fast Skin Material+Displace (mi), and I’m using Mental Ray to render.

First of all, what is the difference between the Tool>Displacement pallet and the Multi Displacement plugin? They seem to share some similar settings, such as DPSubPix. Are they related? Is it necessary to use both in tandem to get good results? What is their relationship?

Secondly, 3ds max 2009 seems to be fickle about the displacement maps it will accept. For example, when I try to bring in a 4k displacement map, I get a File I/O Error. But if I export the map out of ZBrush at 2k, max will accept it. I’m just concerned that a 2k map won’t give me the fidelity I want. Any suggestions on this are appreciated.

Third, the settings in 3ds max that are recommended in the ZBrush Docs don’t seem to work well for me. Specifically, using a value of 220 for the Extrusion Strength in the Displacement Material, and 220 for the Max Displace in Render Setup. Using the 220 value for both of those parameters makes my displacement way WAY blown out and it looks terribly inflated. I left the Render Settings>Max Displace at 220 and lowered my Extrusion Strength to 30 and that seems to put things about where they should be. But that concerns me because it’s such a major deviation from what is being advised in the Docs. I’d like to know why the 200 value isn’t working for me. I’d also like to have a better understanding of how these two parameters are related. Are they additive?

Lastly, I’ve been able to get the major forms to displace, but my tertiary details (wrinkles, pores, etc) are not showing up in my 3ds max render. They may be attributed to me using a 2k displacement map. But, again, max won’t take a 4k map for some reason.

Sorry for the long post. Thanks for any help.

Dustin

#2

I’m answering my own questions to the best of my ability after some more experimentation.

First of all, what is the difference between the Tool>Displacement pallet and the Multi Displacement plugin? They seem to share some similar settings, such as DPSubPix. Are they related? Is it necessary to use both in tandem to get good results? What is their relationship?

Tool>Displacement is for creating a map from one UV space, Multi Displacement plug-in is for creating maps from multiple UV spaces. Also, Multi Displace bakes in the displacement scale, whereas Tool>Displacement requires that you note the Alpha Depth Factor to use later in your render software.

Secondly, 3ds max 2009 seems to be fickle about the displacement maps it will accept. For example, when I try to bring in a 4k displacement map, I get a File I/O Error. But if I export the map out of ZBrush at 2k, max will accept it. I’m just concerned that a 2k map won’t give me the fidelity I want. Any suggestions on this are appreciated.

My experience is that max will only import 32-bit displacement maps up to 2k. If you need a larger map you’ll need to export it out of ZBrush as 16-bit.

Third, the settings in 3ds max that are recommended in the ZBrush Docs don’t seem to work well for me. Specifically, using a value of 220 for the Extrusion Strength in the Displacement Material, and 220 for the Max Displace in Render Setup. Using the 220 value for both of those parameters makes my displacement way WAY blown out and it looks terribly inflated. I left the Render Settings>Max Displace at 220 and lowered my Extrusion Strength to 30 and that seems to put things about where they should be. But that concerns me because it’s such a major deviation from what is being advised in the Docs. I’d like to know why the 200 value isn’t working for me. I’d also like to have a better understanding of how these two parameters are related. Are they additive?

The Extrusion Strength and Max Displace should be set at the same value. The value you use is dependent on the settings you use in ZBrush to export the displacement map. I’ve been doing a lot of experimenting and exporting map after map with various settings, and I’ve had to adjust those two values in max pretty regularly to compensate for any changes I made when I exported the latest map out of ZBrush. 0.22, 2.2, 22.0, and 220 all seem to be sweet spot numbers for some strange reason.

Lastly, I’ve been able to get the major forms to displace, but my tertiary details (wrinkles, pores, etc) are not showing up in my 3ds max render. They may be attributed to me using a 2k displacement map. But, again, max won’t take a 4k map for some reason.

I’m using a 4k, 16-bit displacement map now, and I also created a bump map to help make the tertiary details pop a bit more.

#3

I don’t use displacements all that often as game engines won’t take them…someday.

Anyway, Back in the day when I used displacements I always use a smaller displacement to basically get the form that I wanted, I would then use bump maps and normal maps to make the details pop. When exporting out huge displacement maps you’re really killing your render times. The displacement is really just for the form and silhouette changes, after that it doesn’t really matter anymore, and there is no reason to eat a 30min render when you could half the map size and use a bump and normal to get the finer details and only eat a 5min render.

Just my 2cents. I can go smoke a cig and wait for a render in 5min, for 30min I might as well go do the dishes and get started on the laundry and bathrooms…hell, I could probably clean the whole house that day while tweeking settings waiting on a 30min render…hell. That’s only 8 renders in a day.

but eh, you see where I am going with this.

#4

Couldn’t agree more. Thanks for the reply.