Extends mesh instances that required custom vertex buffers to create two alternating buffers that are written to and binds them to use them as the previous vertex buffer when generating motion vectors.
There was an error in the other branch of the refactored function where the size of the array was not properly multiplied by the size of the float to check against the buffer size. This was only an error in the error-checking itself and not the functionality. There was also an error where the proper notification was not emitted whenever the buffer for the multimesh is recreated to invalidate the previous references the renderer might've created to it. This fixes CPU Particles getting corrupted when they're created without emission being enabled.
Direct buffer copies are required to perform certain operations more efficiently, as the only current alternative is to download the buffer to the CPU and upload it again. As the first use case, the new function is used when enabling motion vectors on multimeshes.
Fixes#67287. There was a subtle error where due to how enabling motion vectors for multi-meshes was handled, only the first instance would have a valid transforms buffer and the rest would point to an invalid buffer. This change moves over the responsibility of enabling motion vectors only when changes happen to the individual 3D transforms or the entire buffer itself. It also fixes an unnecessary download of the existing buffer that'd get overwritten by the current cache if it exists. Another fix is handling the case where the buffer was not set, and enabling motion vectors would not cause the buffer to be recreated correctly.
This is needed to allow 2D to fully make use of 3D effects (e.g. glow), and can be used to substantially improve quality of 2D rendering at the cost of performance
Additionally, the 2D rendering pipeline is done in linear space (we skip linear_to_srgb conversion in 3D tonemapping) so the entire Viewport can be kept linear.
This is necessary for proper HDR screen support in the future.
See Issue #69528. When building with precision=double, the TAA pass would break due to the motion vectors being corrupted. It was apparent the origin of the camera itself was corrupted in the UBO for the previous frame because the camera origin was only being split correctly for the current block but not for the previous block (to effectively support the double precision float on the shader).
Fixes bug where bounding box of 1 unit was used in some skinned models and had wrong LODs.
(this could become very large if the mesh is scaled, such as FBX conversions)
Also fixes a mistake in calcualting bone index.
