USD importer ignores camera near clipping plane #116346

New Issue

Matt-M · 2023-12-19T15:19:02+01:00

Matt-M commented

2023-12-19 15:19:02 +01:00

System Information
Operating system: Linux-6.2.0-1017-lowlatency-x86_64-with-glibc2.38 64 Bits, X11 UI
Graphics card: Quadro RTX 6000/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 535.129.03

Blender Version
Broken: version: 4.0.2, branch: blender-v4.0-release, commit date: 2023-12-05 07:41, hash: 9be62e85b727

Short description of error
When importing a USDA file into Blender which defines a camera prim, the camera FAR clipping plane is imported correctly, but the NEAR clipping plane is ignored completely and set to the default of 0.1 regardless of file contents.

Exact steps for others to reproduce the error

Create a Blender scene which contains only a single camera.
Set the camera to have distinctive values for the near and far clipping planes (e.g. 56 and 12345).
Export the scene to a USDA file.
Confirm the the USDA file has the correct exported values in the camera prim's "clippingRange" attribute.
Start a new Blender scene.
Import the USDA file created in step 3.
Examine the clipping planes of the camera object in the Blender scene.

Expected: The Blender camera object should have the clipping planes set in step 2 (e.g. 56 and 12345).

Actual: The Blender camera object has the correct FAR clipping plane (12345) but the NEAR clipping plane is set to 0.1.

Additional:

Confirmed by examining the code in source/blender/io/usd/intern/usd_reader_camera.cc:

/* Call UncheckedGet() to silence compiler warnings.
 * Clamp to 1e-6 matching range defined in RNA. */
bcam->clip_end = clippingRangeVal.UncheckedGet<pxr::GfVec2f>()[1];

Only the clip_end value is being set, and only the [1] index of the clippingRangeVal is being accessed (i.e. the Y coordinate of the GfVec2f, which in this case corresponds to the far clip distance).

**System Information** Operating system: Linux-6.2.0-1017-lowlatency-x86_64-with-glibc2.38 64 Bits, X11 UI Graphics card: Quadro RTX 6000/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 535.129.03 **Blender Version** Broken: version: 4.0.2, branch: blender-v4.0-release, commit date: 2023-12-05 07:41, hash: `9be62e85b727` **Short description of error** When importing a USDA file into Blender which defines a camera prim, the camera FAR clipping plane is imported correctly, but the NEAR clipping plane is ignored completely and set to the default of 0.1 regardless of file contents. **Exact steps for others to reproduce the error** 1. Create a Blender scene which contains only a single camera. 2. Set the camera to have distinctive values for the near and far clipping planes (e.g. 56 and 12345). 3. Export the scene to a USDA file. 4. Confirm the the USDA file has the correct exported values in the camera prim's "clippingRange" attribute. 5. Start a new Blender scene. 6. Import the USDA file created in step 3. 7. Examine the clipping planes of the camera object in the Blender scene. Expected: The Blender camera object should have the clipping planes set in step 2 (e.g. 56 and 12345). Actual: The Blender camera object has the correct FAR clipping plane (12345) but the NEAR clipping plane is set to 0.1. Additional: Confirmed by examining the code in source/blender/io/usd/intern/usd_reader_camera.cc: ``` /* Call UncheckedGet() to silence compiler warnings. * Clamp to 1e-6 matching range defined in RNA. */ bcam->clip_end = clippingRangeVal.UncheckedGet<pxr::GfVec2f>()[1]; ``` Only the clip_end value is being set, and only the [1] index of the clippingRangeVal is being accessed (i.e. the Y coordinate of the GfVec2f, which in this case corresponds to the far clip distance).

Matt-M added the

labels 2023-12-19 15:19:03 +01:00

Philipp Oeser commented

2023-12-19 16:08:34 +01:00

Can confirm, this somehow got swallowed in 7a9284107d [I mean, the corresponding clamping comment is already there :) ]

Can confirm, this somehow got swallowed in 7a9284107d9789ce6fd735baf1dbe44e4447a7d2 [I mean, the corresponding clamping comment is already there :) ]