Hair particles no longer render curves with geometry #97410

New Issue

Mircea Kitsune · 2022-04-17T16:49:27+02:00

Mircea Kitsune commented

2022-04-17 16:49:27 +02:00

System Information
Operating system: Linux-5.17.1-3-MANJARO-x86_64-with-glibc2.35 64 Bits
Graphics card: AMD Radeon RX 570 Series (POLARIS10, DRM 3.44.0, 5.17.1-3-MANJARO, LLVM 13.0.1) AMD 4.6 (Core Profile) Mesa 21.3.8

Blender Version
Broken: version: 3.1.2, branch: makepkg (modified), commit date: 2022-03-31 17:40, hash: cc66d1020c
Worked: 2.79

Short description of error
When using a curve with geometry as the rendered item of a hair particle system, the hairs no longer show up. They start appearing if the path is converted to a mesh, which is something the artist will sometimes not want to do. This worked in the latest version of Blender 2.x where I used it before, it likely broke somewhere in Blender 3.x.

Attached is a simple blend that replicates the issue: The plane contains a particle system instancing a collection that contains the path. On its own the curve's geometry can be seen clearly, however the particle system refuses to replicate it. It will show up once you select the curve and use Object - Convert - Mesh.

untitled.blend

Exact steps for others to reproduce the error
Create a plane and a curve. Give the curve some depth in its geometry section. Place the curve in a new collection. Create a new particle system on the plane. Set it to hair, in the render section pick to render as a collection, set our curve's collection as the instance collection. The curve should be replicated by each hair yet nothing is seen.

**System Information** Operating system: Linux-5.17.1-3-MANJARO-x86_64-with-glibc2.35 64 Bits Graphics card: AMD Radeon RX 570 Series (POLARIS10, DRM 3.44.0, 5.17.1-3-MANJARO, LLVM 13.0.1) AMD 4.6 (Core Profile) Mesa 21.3.8 **Blender Version** Broken: version: 3.1.2, branch: makepkg (modified), commit date: 2022-03-31 17:40, hash: `cc66d1020c` Worked: 2.79 **Short description of error** When using a curve with geometry as the rendered item of a hair particle system, the hairs no longer show up. They start appearing if the path is converted to a mesh, which is something the artist will sometimes not want to do. This worked in the latest version of Blender 2.x where I used it before, it likely broke somewhere in Blender 3.x. Attached is a simple blend that replicates the issue: The plane contains a particle system instancing a collection that contains the path. On its own the curve's geometry can be seen clearly, however the particle system refuses to replicate it. It will show up once you select the curve and use Object - Convert - Mesh. [untitled.blend](https://archive.blender.org/developer/F13006428/untitled.blend) ![Screenshot_20220417_174216.png](https://archive.blender.org/developer/F13006434/Screenshot_20220417_174216.png) **Exact steps for others to reproduce the error** Create a plane and a curve. Give the curve some depth in its geometry section. Place the curve in a new collection. Create a new particle system on the plane. Set it to hair, in the render section pick to render as a collection, set our curve's collection as the instance collection. The curve should be replicated by each hair yet nothing is seen.

Mircea Kitsune commented

2022-04-17 16:49:27 +02:00

Added subscriber: @MirceaKitsune