Unfortunately I must inform you that your information were incorrect.
I found the error myself.

It's working! But only for the mesh where the hair was being build on.
So when add hair to a mesh and add the collider tag to that exact mesh the collisions are working even with the brush.

So there might be a little bug, that other meshes are not considered.... What do you think?

Hey Maxon,

since new MacOS, I guess since Sequoia, the C4D-File Thumbnail Previews in Finder are not working anymore. I researched a little and apparently Apple did change some stuff and Thumbnails for some other file formats are also not working.

Are you aware of this? Are you able to fix this?

Best and thanks!

Thanks for the reply. But it was doable in previous versions?

https://www.dropbox.com/scl/fo/nu7nl1nmxcx7ei3yz3cpb/AHv4S5x2A1PAB9gV8SpfB48?rlkey=f3d54umdma2xkqcjelwt9ufd6&dl=0

Here a link with screenshots and the file.

Hi there,

on the new versions of C4D (2026 and above) I have experienced an issue with the Hair Brush (set on Move) and Collisions on another Mesh.

I have setup up everything correctly. Hair collider tag and checked the Collisions in the Brush itself. It worked in previous versions. Can you tell me if there were made any changes or do I need to change any settings?

Important info: Collisions are working fine when Simulating /Animatic the Hair. Collisions just not working with the Brush Tool.