Sogs decompress fix

[slimbuck]

For scenes without spherical harmonics.

[Copilot]

Pull Request Overview

This PR fixes the decompression behavior for scenes without spherical harmonics by ensuring that spherical harmonics image data (labels and centroids) is only read when applicable.

• Moved the asynchronous image data reading for sh_labels and sh_centroids into a conditional block that checks if shBands > 0.
• Removed the unnecessary reads outside the condition for scenes that do not use spherical harmonics.

Comments suppressed due to low confidence (2)

src/scene/gsplat/gsplat-sogs-data.js:240

• Moving the readImageDataAsync call into the conditional block limits the processing to scenes with spherical harmonics. Please double-check that downstream code does not rely on sh_labels being initialized when shBands is 0.

            sh_labels._levels[0] = await readImageDataAsync(sh_labels);

src/scene/gsplat/gsplat-sogs-data.js:241

• Ensure that moving the read for sh_centroids into the conditional block aligns with the expected behavior when spherical harmonics are not used and that no downstream functionality is adversely affected.

            sh_centroids._levels[0] = await readImageDataAsync(sh_centroids);