Multimap exporter and merging maps

[rixh]

Hey guys,

I was just trying to get some displacement maps out of Zbrush using the multimap exporter which I’ve done a few times before, but this time I have multiple subtools and for some reason the merge maps and subtools options causes me to get a weird error before it bakes out. Also the resulting maps are separated into subtools and don’t merge, so for subtool 1 I’d get UDIM 1001-1006 then for subtool 2 I’d get a seperate UDIM 1002 and they don’t merge together.

Another issue I’m having is where information is being baked for a subtool that has only been subdivided and there shouldn’t be any displacement information. I think I remember a while ago that there was a fix around this by storing a morph target at the lowest subdivision then turning on the “switch MT” option.

Thanks in advance for any help I can get,
Richard

Ps. Woops forgot to add images

[Spyndel]

Hello!

To answer part of your question, yes you do need to store a morph target for each subtool if you are working with a mesh with existing UVs that must remain exactly the same (for instance, if it is rigged in another program). Just the act of subdividing will cause subtle changes in the mesh across all SubD levels. You will need to switch back to the original MT at the lowest SubD level for generating the maps, and then switch back to the slightly altered low poly base before changing SubD levels again, or your MT will be altered.

The prescribed workflow is:

1. Go to subdivision level 1.
2. Store a Morph Target by pressing Tool >> Morph Target >> Store MT.
3. Import original mesh.
4. Set the plugin options, making sure the ‘Switch MT’ button is on.
5. Press ‘Create All Maps’ to start plugin operation.

If there are no such concerns, then a MT should not be necessary. You should be able to export the maps based on whatever the current low poly base is, as long as you are also exporting that base to apply them to and the UVs are specifically created for it. You get issues when the UVs were created for a slightly different version of your Low poly base.

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As far as the maps not merging, are the all the same size? Only maps of the same size will be merged.

[rixh]

Hey Spyndel thanks for the reply!

Thinking about your comment on MT not being necessary I realised it’s probably something else causing my displacement problems. I did a few tests but I’m still having problems bringing my displacement maps into maya so I’m not sure if I’m doing something incorrectly in zbrush or in Maya.

As you can see I’m getting some pretty bad displacement seams, I simply started with a cube and a few supporting edges,

subdivided it a few times with smt on but Suv off

exported my resulting low level mesh out,

UV’d the mesh and unfolded to make sure there isn’t any stretching

Reimported the mesh at level 1 and then exported out displacement maps with Smooth UV not selected

Setting my maya displacement properties to linear subdivision and rendering it I get those problems.


Not sure why I’m getting these issues, plus if I put autobump on I get really bad banding… I was just wondering if its because my base mesh has geo that varies significantly to final displacement.

This is another issue that I’m not sure if its related but the exact same process was done on this and I’m getting some weird inflation. For this I even tried Smooth UV on in the displacement export and setting Maya displacement properties to Smooth but I get this problem either way. It just seems like theres alot of information in the displacement map that shouldn’t be there which is why I was thinking the MT approach would fix that

Sorry for the long as post, It’s just been doing my head in a bit…
Thanks again for your help!

[rixh]

I just found out that I can merge the maps with the “exr” option turned off which is less then ideal cause what i get is just a tif… if the “exr” option is on then I get the vector displacement/displacement merge error…