Fixes misalignment in motion vectors from TiledCamera (#2012)

# Description

I find the rendered motion_vectors (or optical flow) are not aligned
with other modalities (such as RGB, depth, segmentation, etc.).
This commit is a workaround to fix this misalignment issue.

Fixes #2003

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## Type of change

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applicable. -->

- Bug fix (non-breaking change which fixes an issue)

## Screenshots

Before:

![image](https://github.com/user-attachments/assets/acd2ba5c-a769-4759-b95b-1c31180355bb)

After:

![image](https://github.com/user-attachments/assets/a7c82707-9862-4c06-a83f-3950cdf7ba14)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

---------
Signed-off-by: Hongyu Li <lihongyu0807@icloud.com>
Signed-off-by: Kelly Guo <kellyguo123@hotmail.com>
Signed-off-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>
Co-authored-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>
Co-authored-by: Kelly Guo <kellyguo123@hotmail.com>

CONTRIBUTORS.md

@@ -55,6 +55,7 @@ Guidelines for modifications:
 * Haoran Zhou
 * HoJin Jeon
 * Hongwei Xiong
+* Hongyu Li
 * Iretiayo Akinola
 * Jack Zeng
 * Jan Kerner

source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.34.7"
+version = "0.34.8"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.34.8 (2025-03-04)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed the issue of misalignment in the motion vectors from the :class:`TiledCamera`
+  with other modalities such as RGBA and depth.
+
+
 0.34.7 (2025-03-04)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/sensors/camera/tiled_camera.py

@@ -259,6 +259,11 @@ class TiledCamera(Camera):
                     ptr=tiled_data_buffer.ptr, shape=(*tiled_data_buffer.shape, 4), dtype=wp.uint8, device=self.device
                 )
 
+            # For motion vectors, we only require the first two channels of the tiled buffer
+            # Note: Not doing this breaks the alignment of the data (check: https://github.com/isaac-sim/IsaacLab/issues/2003)
+            if data_type == "motion_vectors":
+                tiled_data_buffer = tiled_data_buffer[:, :, :2].contiguous()
+
             wp.launch(
                 kernel=reshape_tiled_image,
                 dim=(self._view.count, self.cfg.height, self.cfg.width),