Environment:

- Character Creator 5.11
- Latest Unity Pipeline Export plugin (installed via Reallusion Hub v2.2.5)
- Latest Unity Auto Setup (GitHub)
- Unity HDRP
- Issue reproduced on both custom assets and Marketplace assets



Summary:

The Unity Pipeline Export fails to generate HDRP packed textures whenever a material does not contain an Ambient Occlusion (AO) texture.

This affects any PBR material, even if all other required textures (Base Color, Normal, Roughness, Metallic, etc.) are present.

The issue is reproducible on:

- Custom clothing
- Marketplace hair assets
- Modified stock assets after removing their AO texture

The same assets export correctly through the Blender Pipeline (CC5 -> Blender -> Unity), which correctly handles missing channels and still exports roughness and generates valid Unity materials.



Issue Description

During Unity Pipeline Export, HDRP mask generation appears to depend on the existence of an Ambient Occlusion texture.

If the AO texture is missing:

- HDRP Mask textures are not generated.
- Roughness information is completely lost.
- Only MetallicAlpha and Displacement textures are generated (along with the regular FBM textures).

As a result, imported materials become significantly glossier than intended because no smoothness/roughness information reaches Unity.



Expected Behavior

The Unity Pipeline exporter should generate HDRP Mask textures regardless of whether an AO texture exists.

If AO is missing, the exporter should simply use a default white AO channel (or another default value), exactly as Blender Pipeline already does.

Missing AO should not prevent Roughness or other channels from being exported.



Actual Behavior

If an AO texture is absent:

- HDRP Mask is not generated.
- Roughness texture is not exported.

Even though the material contains a valid Roughness texture inside Character Creator.

Only the following HDRP-related textures are exported:

- MetallicAlpha
- Displacement



Steps to Reproduce

Case 1 – Custom asset:

1. Create or import a custom clothing asset.
2. Assign: Base Color, Normal, Roughness, ...
3. Leave Ambient Occlusion empty.
4. Export using Unity Pipeline Export.

Result:

- HDRP Mask is missing.
- Roughness is missing.

Case 2 – Same asset with AO:

1. Assign any image (even a random placeholder) into the AO slot.
2. Export again using Unity Pipeline Export.

Additional testing shows that the AO texture does not need to contain valid ambient occlusion data. Assigning a completely white AO texture is sufficient for Unity Pipeline Export to generate the HDRP Mask correctly. This indicates that the exporter likely checks only for the existence of an AO texture rather than requiring meaningful AO data.

Result:

- HDRP Mask is generated correctly.
- Roughness is exported correctly.
- Materials import into Unity as expected.

The only change between the two exports is the presence of an AO texture.

Case 3 – Stock CC asset:

1. Take any stock Character Creator asset that normally exports correctly.
2. Remove its Ambient Occlusion texture.
3. Export using Unity Pipeline Export.

Result:

- HDRP Mask generation also fails.

This demonstrates that the issue is not related to custom assets.



Comparison with Blender Pipeline

Using the same character and the same materials:

- Blender Pipeline exports Roughness correctly.
- Blender Pipeline exports materials correctly even without AO.
- Exporting from Blender to Unity also produces correct Unity materials.

This demonstrates that:

- The Roughness texture exists.
- Character Creator stores it correctly.
- The material itself is valid.
- Only Unity Pipeline Export fails to process it when AO is missing.



Additional Notes

This issue also affects Marketplace assets.

Several Marketplace hair assets exhibit the exact same behavior:

- No AO texture → no HDRP Mask generation
- Adding an AO texture immediately restores correct export

This suggests the issue is related to the Unity Pipeline exporter's texture packing logic rather than any specific asset.



Why this appears to be a bug

- HDRP Mask generation should not depend on the presence of an Ambient Occlusion texture.

- Texture packing should still proceed using available channels and substitute default values for any missing ones.

- Current behavior causes valid PBR materials to lose Roughness information entirely, resulting in incorrect materials inside Unity.