Displacement Map creation using Maya Transfer Maps

[mayanim8]

I am hoping someone can help.  I have been trying to understand and how to problem solve and figure out the process of creating displacement maps using Maya's Transfer Maps.  I have tried to follow instruction in the help sites, but the results I'm getting are not really what I assumed I should be getting.

To simplify the process, I model a simple object in a free sculpting software and roughly textured it. 

The object was exported as an OBJ and imported it into Maya, 2018.3

In Maya I used Quad Draw to rough out a very low resolution model.

UV mapped it.

I am using Arnold 51.101,  MtoA 3.0.0.2

I am able to create some kind of displacement map, but the result are not really that great; the rendered displaced geometry has a lot of artefacts as well, the high points are flattened out. 

I am not sure if I understand exactly how much information I can actually get from a displacement map?

I'm not sure if my process is correct.

I can supply a file if you wish.

I have included an image showing the settings in the Transfer Maps as well as the resulting render compared to the original high Resolution.

I am trying to only use Autodesk products to create the maps.

If anyone can help I would greatly appreciate it.

thank you

[jordan.giboney]

Hi @mayanim8 

Thanks for posting! Could you share the tutorial that you are going through and what version of Maya you are working with? 🙂 I would love to test out the same workflow on my end.

I also found a couple more tutorials that may help clear things up:

• Creating a normal map with transfer maps tool in maya
• Maya - Arnold: Displacement Baking

Thanks again for being a part of our community!

[jordan.giboney]

Hi @mayanim8 

Thanks for your direct messages! After looking at your image and speaking with my colleague, we think that baking a normal map instead would be more successful. Could you give this a shot and let us know the results? You may also benefit from adding more geometry to your mesh.

And you're right, the more common workflow for projects like this is to use another software in combination with Maya. One *free* option for additional software is xnormal - this tool includes baking normals, displacement maps and ambient occlusion. 

Let us know if you need more info! We would be happy to continue assisting 🙂

[mayanim8]

Thank you for your information.
With regards to adding geometry to the low rez mesh. Does not raising the Arnolds Shape Node Attribute: aiSubdivIterations on the low resolution mesh do the same thing? Or do I have to subdivide the surface and then in addition raise the aiSubdivIterations attribute?

I ran the Transfer Maps/normal and created an image that looks fine.  Unfortunately, my post is not a specific request to fix a specific example. The image posted was a very simple test I created to try and understand how to create displacement maps using Maya's transfer maps.
I have been unable to figure out why the Maya Transfer Maps are yielding the results I have posted. I am not sure if this is because the high resolution mesh is causing problems or if there is something wrong with the settings used to create the map?

[jordan.giboney]

Hi @mayanim8 

Could you share an image of the results you get with normal maps? A height map alone will not make your mesh appear like a high poly.

The scenario you are describing would best benefit from using a normal map - the level of detail, that is. A normal map will do 90% of the work, but a combination of that with AO and height map all working together is the ideal scenario (one single part of this combination may be insufficient depending on you desired results).

Let me know if this makes sense 🙂 Thanks again for being a part of our community!

[mspeer]

Hi!

For me it looks like a problem of sampling.

The chosen file format + the maximum height value that will be used to create the displacement map results in this stepped view.

I haven't used this tool for a while, but the best would be to choose a 32-bit file format (not sure if this is possible here) or at least 16-bit and use the optimal value for height / "Maximum Value" (set it to 0 for auto scale).

And of course use a larger image size (i recommend at least 2048 x 2048).

[jordan.giboney]

Hi @mayanim8 

I hope you are doing well 🙂 I wanted to check in and see how things were going. Did the information I posted make sense? Did you have a chance to try out @mspeer's suggestions?

We would be happy to help with any follow up questions you may have, or, if you have found a solution please mark the post that best describes it (or post a new reply). Marking the solution helps our other forum users find answers quickly!

Thanks again for being a part of our community!

[mayanim8]

Hello,

Thank you to everyone who has been trying to help.

Forgive the delayed response, I have been testing out the various solutions that were provided to me.

Here is what I seem to have discovered:

1. the geometry's scale:  the object was very small, and once it was scaled up, the resulting displacement map was producing results that appear to be more familiar.  There seems to be a Goldilocks zone; if the object is too large or too small the displacement map creation gets odd.

2. Poly count of the low resolution model was too low.  However, even when increased artefacts are still present. 

3. EXR, Using the exr setting in the transfer maps Output Maps, appears to cause problems.  When EXR is used, Arnold does not seem to be able to create a .tx file or open it.  As well, TIFF16 is not listed in the File Format in the Output Maps, however it is listed when you go into the File Save window.  Then, the EXR file type is not listed, and regular Tiff is not listed.

I am including a document that I hope will show what I have been experiencing.

Also, If someone could address the issue with the artefacts - wave pattern shown in the images provided.

Based on what I have been reading, it appears that people often manually open the file and blur out the artefacts.

Regards

[mayanim8]

Information was left out from the previous posting.  This may also be an issue with the file formats in Transfer Maps .

When an map is created and the TIFF 16 file format has been set.  The resulting image when opened in Photoshop is an 8 bit image, not a 16 bit image.

[mspeer]

Hi!

OK i tested it now.

EXR seems not to work (maybe a problem of removing Mental Ray, cause Maya Software does not support EXR).

Please report this problem (bug?) to Autodesk.
In Maya main menu:
Help -> Speak Back -> Report a Problem

For a better map / look:

1. Make sure to use a low value for Output Maps -> Maximum Value

(in my test with a default sphere a good value was "0.05".)

2. Make sure Arnold subdivides the object and does not use Auto Bump.

[mayanim8]

Thank you for your help

I will report the problem.