UV Mapping Issue with LOD Levels in RenderFidelity Performance Mode

[CilginnImam (Imam)]

Description:
When using a custom wheat model in Roblox Studio, a UV mapping issue occurs when the “RenderFidelity” setting is set to “Performance” mode, and LOD levels are previewed (e.g., “Level 03 LOD”). The texture displays incorrect regions of the atlas, as if the UVs are being recalculated or distorted. This issue consistently appears across multiple imported models. The texture is a simple 4096x4096 atlas, and the UVs are scaled to zero, positioned over specific regions of the atlas. The model has the “Double Sided” property enabled, with no other settings modified.

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Steps to Reproduce:

1. Prepare the Model:

   • Create a 3D model with UVs scaled to zero and placed over specific regions of a 4096x4096 texture atlas.
   • Use a single material and texture for the model.
   • Enable the “Double Sided” property for the model.

2. Import into Roblox Studio:

   • Import the model into Roblox Studio using the Asset Manager or by dragging it into the workspace.
   • Verify that the texture atlas is correctly applied to the model.

3. Adjust RenderFidelity Settings:

   • Select the model in the Explorer.
   • Set the “RenderFidelity” property to “Performance.”

4. Preview LOD Levels:

   • Set the MeshDetail level to “Level 03” or any other lower LOD level.

5. Observe the Issue:

   • Notice that the texture appears incorrect, showing regions of the atlas that do not align with the original UV mapping.

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Expected Behavior:
The UV mapping should remain consistent across all LOD levels, displaying the correct regions of the texture atlas as defined by the original UV layout.

Actual Behavior:
At lower LOD levels, the UV mapping appears distorted, leading to incorrect texture display.

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Additional Notes:

• The issue is reproducible with multiple custom models using similar UV setups.
• The texture atlas is a standard 4096x4096 PNG file.
• No scripting or additional properties (aside from “Double Sided”) were used.

Attachments:

A private message is associated with this bug report

[thirdtakeonit]

Thanks for the report! I filed a ticket in our internal database and we’ll follow up when we have an update for you.

[narheas]

Hi @CilginnImam, could you provide the 3d model or the place file for investigation? Thanks!

[narheas]

Hi @CilginnImam,

The “Performance” setting aggressively simplifies meshes to boost performance, which can unfortunately lead to UV distortion as a trade-off.

If the arrows in your third image indicate the leaf and stem colors, the distortion is likely happening because the simplification process interpolates UV coordinates within the texture space.

We’re actively working on improving this algorithm and expect to release an update soon. In the meantime, we recommend either using the “Automatic” setting or rearranging your texture map so the color blocks for leaves and stems are contiguous.

[CilginnImam (Imam)]

Hi @narheas,

Thanks for the explanation. Do you still need the 3D model/place file?

[narheas]

Hi @CilginnImam,

If the arrows in your third image indicate the leaf and stem colors then this is how the feature works. Please keep an eye on the update of the feature later this year!