Importing Model Ignores Custom Normals?

Development Asset Creation
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1

I could be going wrong somewhere so would appreciate any advice.

Running into an issue on a RC decimated 50k model where I want to use Blender to auto smooth the model (example below)

Capture2
Capture22353×1512 271 KB

When I bring the models into Unreal they look correct in Lighting only mode

Capture3
Capture32443×1306 204 KB

When I switch to detail lighting with the normal maps I get artefacts on anything other than the smooth shaded version (straight RC model)

Capture4
Capture42446×1306 243 KB

I’m guessing this is because the normal maps (generated with the Texture Reprojection tool) were done on the smooth model. So when I import the custom auto model back into RC from Blender it shades it the usual flat shaded so I’m assuming the custom normals are being ignored? If I import back to Blender its what I expect so can you tell me if RC totally ignores the obj custom normals?

Thanks!

2

Could you please give more information about your workflow and what you are trying to achieve? Not sure what you mean by the “RC totally ignores the obj custom normals”. RealityCapture creates normal maps during the texture projection, and they are made based on the model from which the reprojection is executed. You cannot reimport normals into RealityCapture, only create them again.

The Flat model is the one that is from RC and not edited in Blender?
Here is an explanation of how the smoothing work with normals in Blender:

"Notice that the outline of the object is still strongly faceted. Activating the smoothing features does not actually modify the object’s geometry; it changes the way the shading is calculated across the surfaces (normals will be interpolated), giving the illusion of a smooth surface.

Select the Shade Flat item in the Object menu to revert the shading back (normals will be constant) to that shown in the first image above"

3

Hi,

If reality capture ignores normals on model import then I’ll have to use another application to generate them.

thanks

4

RealityCapture generates normals from a model that exists in RealityCapture. Even though you cannot import them, you can still generate them.

The issue you have is probably that the smoothing in Blender interpolates normals.

5

yes exactly that, I can import those meshes from Blender into Unreal but the normal maps that are RC generated are on the soft normals of the RC model so I get the mismatch.

To me its a feature request / bug as you can import models into RC but it strips that information off (should be optional). I’m going to stick to the RC model for the moment and increase the model resolution to work around the issue.