Cycles point cloud geometry on non-point-cloud object lacks deformation motion blur #94245

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RoyTheKoi · 2021-12-19T07:29:07+01:00

RoyTheKoi commented

2021-12-19 07:29:07 +01:00

System Information
Operating system: macOS Big Sur 11.2.3
CPU: 2.3 GHz 8-Core Intel Core i9
Graphics card: AMD Radeon Pro 5500M 8 GB

Blender Version
Broken: 3.1 Alpha, 214a56ce8c, master, 2020-12-17

Short description of error
Points generated via geometry nodes on an object that is not itself a point cloud (e.g. a mesh or other type) lack deformation motion blur when rendered with Cycles.

Conversely, if the object is a point cloud it will successfully render points with deformation motion blur, even if they were generated via geometry nodes.

The source of the deformation doesn't seem to matter, only whether or not the object is of the point cloud type. I tried deformation from both geometry nodes and a displacement modifier.

In the example above, the same geometry nodes modifier is used on both a mesh and a point cloud object. The modifier both generates and rotates the points. As shown, only the point cloud object displays deformation motion blur.

As an aside: I also noticed that meshes generated with geometry nodes on point cloud objects do not have deformation motion blur.

Exact steps for others to reproduce the error
Cycles_point_cloud_deformation_motion_blur.blend
Open the attached blend file and hit F12 to render, or:

Open Preferences -> Interface -> Display -> enable Developer Extras
Then under Preferences -> Experimental -> Prototypes -> enable New Point Cloud Type
Create both a mesh object and a point cloud object, then move them apart.
Add the same geometry nodes modifier to both objects
In the geometry nodes modifier add an icosphere node, followed by a mesh to points node
Add a transform node after the mesh to points node
Animate one of the values on the transform node, for example using keyframes or a "frame" driver.
Under Render Properties set the render engine to Cycles and enable Motion Blur.
Adjust the camera if needed to see both objects then render the image with F12
The points generated by the mesh object won't show deformation blur while those generated on the point cloud object will.

**System Information** Operating system: macOS Big Sur 11.2.3 CPU: 2.3 GHz 8-Core Intel Core i9 Graphics card: AMD Radeon Pro 5500M 8 GB **Blender Version** Broken: 3.1 Alpha, 214a56ce8c67, master, 2020-12-17 **Short description of error** Points generated via geometry nodes on an object that is not itself a point cloud (e.g. a mesh or other type) lack deformation motion blur when rendered with Cycles. Conversely, if the object is a point cloud it will successfully render points with deformation motion blur, even if they were generated via geometry nodes. The source of the deformation doesn't seem to matter, only whether or not the object is of the point cloud type. I tried deformation from both geometry nodes and a displacement modifier. ![Cycles_point_cloud_deformation_motion_blur_nodes.png](https://archive.blender.org/developer/F12762700/Cycles_point_cloud_deformation_motion_blur_nodes.png) ![Cycles_point_cloud_deformation_motion_blur_render.png](https://archive.blender.org/developer/F12762702/Cycles_point_cloud_deformation_motion_blur_render.png) In the example above, the same geometry nodes modifier is used on both a mesh and a point cloud object. The modifier both generates and rotates the points. As shown, only the point cloud object displays deformation motion blur. As an aside: I also noticed that meshes generated with geometry nodes on point cloud objects do not have deformation motion blur. **Exact steps for others to reproduce the error** [Cycles_point_cloud_deformation_motion_blur.blend](https://archive.blender.org/developer/F12762724/Cycles_point_cloud_deformation_motion_blur.blend) Open the attached blend file and hit F12 to render, or: 1. Open Preferences -> Interface -> Display -> enable Developer Extras 2. Then under Preferences -> Experimental -> Prototypes -> enable New Point Cloud Type 3. Create both a mesh object and a point cloud object, then move them apart. 4. Add the same geometry nodes modifier to both objects 5. In the geometry nodes modifier add an icosphere node, followed by a mesh to points node 6. Add a transform node after the mesh to points node 7. Animate one of the values on the transform node, for example using keyframes or a "frame" driver. 8. Under Render Properties set the render engine to Cycles and enable Motion Blur. 9. Adjust the camera if needed to see both objects then render the image with F12 10. The points generated by the mesh object won't show deformation blur while those generated on the point cloud object will.

RoyTheKoi commented

2021-12-19 07:29:07 +01:00

Added subscriber: @RoyTheKoi