We captured RAW files using the Fullbody Scan Rig at 3D Scan Studio Iris, calibrated them, and generated OpenEXR files in ACEScg format. Instead of using photogrammetry, we used the calibrated OpenEXR files to create Gaussian splatting (PLY) in post-processing.

I created a simple sample movie by loading the generated Gaussian Splatting into the After Effects plugin (Postshot / Irrealix Gaussian Splatting).

It's shocking how the "transparent vinyl umbrella" and the "background" are completely separated, which is impossible with photogrammetry. While the resolution of materials is significantly reduced compared to photogrammetry, Gaussian Splatting can provide powerful expressions depending on the purpose.

Postshot Notes

We are currently using the latest beta version v0.3.99 for postshot. With this version, when using standard sRGB materials such as JPEG, issues may arise such as pre-process linearization or brightness saturation due to mixed focal lengths.

For this sample, we generated Splats using 118 OpenEXR files with mixed focal lengths in 16-bit float. When pre-converted to linear gamma, there was no brightness saturation in postshot v0.3.99.

About Color
We imported splats using the plugin (Postshot / Irrealix Gaussian Splatting) in AE, and the colors appeared almost identical immediately after import.

Dynamic Range
In AE, with project bits set to 8/16-bit, it seemed that pixels above 1 in the splat were clipping. Switching to 32-bit float slightly restored the clipping in the brighter areas, and it's possible to restore brightness using a 32-bit compatible plugin.

About Splat Quality
In terms of versatility, "Irrealix Gaussian Splatting," which allows post-processing such as cropping, is convenient, and the "Postshot plugin" seems to have slightly better image quality, though it's simpler in function.

About Scale
Splats loaded with Irrealix Gaussian Splatting appear smaller, and adjusting the AlignScale to about 191% brings it to a similar size as Postshot. While the two don't align perfectly, they nearly match with scale adjustment alone, so there doesn't seem to be a significant positional discrepancy.

GPU Memory Consumption
Using a composition specification of 3 layers through the Postshot plugin and 1 layer for Irrealix Gaussian Splatting, the GPU memory consumption is over 9GB. Even if compressed types of splat formats become more common, it seems they will always consume a significant amount of GPU memory during operations.

Compatibility of Postshot Plugin and AE
The Postshot plugin may only work in AE2023 and did not function in AE2024 on our Windows environment.

As of yesterday, 5/8, Postshot v0.3.116 was released, and we will continue to evaluate it.

#postshot

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