Displacement Maps

This method uses Mental Ray.

Making the low poly model in max

Model so if turbosmooth is applied, the model looks as expected ... make edges close where you want a crease, only 4 sided polys, etc:

 

Export as an OBJ and import to ZBrush.

In ZBrush

Before sculpting, Store Morph Target

Sculpt at SubDiv 6 or so ...

Go back to SubDiv 1

Morph Target/Switch to restore the original vertex positions at the lowest subdivision level.

The sculpting at higher levels will not be affected.

After restoring the morph target, the low-res model is the same as the original.

  

Hit AUVTiles (Automatic tiles)

 

Tool/Displacement ...

Set to 2048 or more.

Note -- ZBrush calculates the displacement  map by comparing the positions of the high-res model with the corresponding points on the low-res model.

Adaptive: automatically determines the additional number of subdivisions that are performed for various regions of the mesh during map generation, depending on the resolution of the mesh in that area.

Smooth UV: If the model has sharp edges that are not maintained in your renders, try making displacement maps with this turned off.

Use this setting and hit Create DispMap:

The map will appear in the Alpha palette ... invert and flip H and V ...
Export a TIFF.

Photoshop
Open the TIFF.
Adaptive displacement tiffs don’t need to be auto-leveled ... but change the mode to RGB.
If you did not Flip vertical in ZBrush, flip vertically and save as 16-bit RGB TIFF -- no compression, color management, embedded profile, etc.
What we are seeing here are the broken up automatic tiles:

 

Note – this is an example of GUVs (Grouped Tiles) and the subseaquent displacement:

 

Note – here is an example of a displace map using original UVs from Max.

 

Back to ZBrush to export the model:
Export the tool at SubDiv 1 as an OBJ and open in max.

In Max

Convert to editable poly:

Material Editor

In Max, turn on mental ray

Create a material with mental ray Connection at the bottom:
Unlock displacement and use 3D displacement (3ds Max)

In Extrusion Map, import your TIFF.

Click on the Extrusion Map slot to edit the bitmap. In the Coordinates rollout set the Blur to 0.01 (prevents banding if you use another renderer such as Vray)

 

You need to either flip vertical the TIFF in Photoshop or ZBrush or do it here (-1.0 V Tiling)

Note: Mental Ray doesn’t use intensity centered by default so setting the RGB offset to -0.5 adjusts the map to allow for centered displacement.

In Output, RGB offset -0.5 (map will look black, negative displacement is still there).

With displacement length 0 and RGB offset 0.0, you will see an opening between faces:

Correct that by setting RGB offset to -.5:

Object Independent: checked
Displacement Length: 1.0
Extrusion strength: apply numbers and see what looks good.

Try using the Alpha Depth factor number as your extrusion strength:

 

mental ray Renderer tab
View: Checked
Edge Length: 1.0
Max Displace: same as extrusion strength or above
Max Level: 16k
Mitchell

Turbosmooth on the mesh

Apply a Turbosmooth with iteration of 1.

  

This example uses subpix2
The TIFF will look completely gray ... in Photoshop apply auto levels
The process is the same as above, but set smooth off in the zbrush displace settings

With 4096 tiff in standard spec level slot... and ray traced shadows ... smoothing off

Example: Displace map 2048 adaptive, turbosmooth smooth result off.