Merge tool in 5.6 bakes the materials incorrectly

Development Cinematics & Media
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If I take the same skeletal mesh in 5.3 and i merge it with the same setting as in 5.6 , the 5.3 version will be perfect while the 5.6 will distort the new UVS or even completely break them, compared to previous version of the engine.

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Steps to Reproduce
Merge tool in 5.6 bakes the materials incorrectly

Take a static mesh with several material slots and merge it , merge the materials on LOD 0 so it gets baked down into one material .

If I take the same skeletal mesh in 5.3 and i merge it with the same setting as in 5.6 , the 5.3 version will be perfect while the 5.6 will distort the new UVS or even completely break them, compared to previous version of the engine.

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Hey there,

I’ve tested your repro with some assets here, relatively simple with Manny and Quinn, where I’ve setup Quinn’s materials to match Manny’s for the merge, and I’m not seeing an issue here outside of what I would expect, (Quinn’s UVs aren’t setup to work with Manny’s textures). Would you be able to share more info? Specifically, screenshot of your settings and setup,an output of the distorted UVs and what you would expect them to look like? Video? Any assets that you can share as well would be helpful, I can also mark the project as confidential if need be.

Dustin

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Hi Dustin,

Thank you for your answer.

You don’t need 2 skeletal meshes though, the use case would be .

In UE 5.3 Get only one skeletal mesh with more than one material slot. Quinn for example but a more complex one would be better.

Make a static mesh.

Get that static mesh and put it in the world by itself. Merge it with itself no need to have a second actor .

Pick LOD 0 and pick Merge materials , so all the materials slots are baked down into one and UVs are redone.

You should get a perfect result.

Now do the same in 5.6 with the same SKM and the same settings.

You will get a much worse result, with distorted UVs [Image Removed]I hope this helps.

Thank you

Sergio

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Thanks for the repro. Unfortunately, I’ve tried a bunch of models and still have been unable to reproduce the issue. For example, here are the stylized character from the 5.3 release in 5.6 and the outputs of both the model and the texture. The far left is the skeletal mesh, the middle is static conversion, the right is merged static.

[Image Removed]Is there anything unique about your model, settings or UVs? Can you share your merge settings? If you can share your model with us, we may be able to address the issue more completely. If necessary, I can make the issue private.

Dustin