3Ds Max Morph Targets with OpenSubDiv?

Raildex

Hi there, I have a Low Poly Model that uses OpenSubDiv.
I'd like to use Morph Targets though. Is there a work Flow to apply Morph Targets even though my Model uses OpenSubDiv?

My stack looks like this at the moment:



I tried to copy the Mesh, do the Vertex Adjustments and use a Morpher in the Original Mesh ontop of OpenSubDiv.
But Morpher had no effect on the Mesh

Eric Chadwick

Well first of all, you should use Collapse To on the Unwrap UVW modifier. This will condense the bottom three modifiers into one Editable Poly, which will make your model less prone to errors (and more performant in the viewport). Nothing is lost when you do this, the UVs are still there.

The trouble with leaving those modifiers there is that they are each dependent on the exact same vertex order coming up to them from below. If you remove or add verts, even by accident, the UVs will be reset, and the Edit Poly will also probably barf.

Anyhow, I would place the Morpher directly below the OpenSubdiv. Just think about the flow of data, upwards through the stack, and it should become evident how it would work best.

Editable Poly provides the base shape > Morpher moves the verts around > OpenSubdiv tesselates and smooths the verts > then Skin moves the verts around even more.

Raildex

Hi there. thanks for the advice and I having the Stack not collapsed is just for adjustments. The UVs are not like I want them to be when using SubDiv, that's why I have an additional unwrap to adjust them how I want them

However, do you know a workflow for easily imporing it into Unreal Engine?
Having Morpher Below the SubDiv, Unreal refuses to import the Morph Targets.
Having a Subdivided Model(Morpher ontop of SubDiv/completely collapsed stack) for Morph Targets is a pain in the ass though(even with Soft Selection)

Eric Chadwick

That's fine to make adjustments, but don't try to keep those modifiers there as a way to "save" a backup. You're in for a world of hurt once it breaks. Always better to collapse as soon as you've made edits, then re-add a new Unwrap modifier next time you want to edit.

What is the exact error you get from Unreal?

Raildex

Eric Chadwick said:

That's fine to make adjustments, but don't try to keep those modifiers there as a way to "save" a backup. You're in for a world of hurt once it breaks. Always better to collapse as soon as you've made edits, then re-add a new Unwrap modifier next time you want to edit.

What is the exact error you get from Unreal?

Thanks for the advice

Unreal doesn't give an error. The Morph Targets just don't appear when importing.

Eric Chadwick

How exactly are you exporting them?

Raildex

Well, what do you mean?
I export the FBX as usual.

Eric Chadwick

Which version of FBX are you using? Are you following the instructions here?
https://docs.unrealengine.com/latest/INT/Engine/Content/FBX/MorphTargets/

Eric Chadwick

Better to export without OpenSubdiv, and use Unreal's own tesselate function.
https://answers.unrealengine.com/questions/11738/request-opensubdiv.html

Raildex

Yes, I also use the same version and tried different versions.

I know how to export/import Morph Targets. It just won't import them if Morpher is below OpenSubDiv.
If Morpher is ontop of OpenSubDiv, it works (I have to make Morph Targets with High Polys, though, which is what I want to avoid) 

Eric Chadwick

So why not tesselate in Unreal?

Raildex

You mean tessellation via Materials?
Afaik Mobile and lower DX/OpenGL versions don't have tessellation.

Eric Chadwick

Why use subdivided models for low-end targets? Download size is larger, loading time is slower, a lot of verts uses up a lot of memory, and CPU/GPU speed is affected too. Doesn't seem like a smart way to go. Have you tested the perf costs yet on your target hardware?

Raildex

I got a somewhat easy workflow now:
Copy the original Mesh as it is for the Morph Target.
Use Edit Poly to change the Facial Expression
Collapse the Stack including OpenSubDiv.
Add Morpher To Original Mesh ontop of OpenSubDiv and add the new mesh to the Morph Channels.
Works like a charm.