I’m trying to generate bevels on acute angles and I can’t get Blender to behave like I’d like to.
As a talking reference, let’s use a cube with one collapsed edge:
When I select 3 edges and bevel them, I end up with not circular bevels in the pointy corners:
What I am looking to achieve is that:
I can get something close by bevelling one by one those non square edges and by playing with the profile shape, but this shows it’s limitations when trying to work on really pointy geometry:
I think your expectation here is off in that the result you get is due to beveling the remaining geometry. The result you want is better described with drawing the three circles first and then using a tool to draw the tangent lines - I have done this in ArtiosCAD with a tool that does just that for drawing packaging.
The initial geometry in the ‘pointy corner’ is only half of what you would need for the bevel operation, so that’s why it just seems to blend to soft curve.
edit: I do think that an addon could help if the addon could calculate the difference as if doing a bool.
I’m stumped, I definitely thought this was possible. @howardt is there any combination of bevel settings that can achieve a circular profile like this ?
My question originated from a geonode setup I’m trying to achieve, and I was dealing with bevel on the mesh outside of the node setup (since I wasn’t finding a “bevel” node in GN). This solves it, but I still would love a way to make it work like this in ordinary bevels. CAD softwares work like that:
Import a triangulated mesh into a cad program and let me know how well it bevels that. The fundamental aspect of how the data is being stored makes certain tasks much harder than others.
Different tools will have different strengths and weaknesses, it’s our job to know which is the best tool to use for each task we are doing.
Cool, but under the hood the CAD software is actively looking for the tangent as part of the design of the bevel - I can say that is what is going on with a similar situation in 2d CAD where I indicate a 1/2 radius blend on a triangle made from a 4" square.
The problem I see is to solve how to get the thing to look for the tangent in Blender - that might have to be a whole new setting option.
edit: I get it now - the CAD and Illustrator calculate by Radius, the Bevel in Blender isn’t doing that, it looks like ‘Width’ is across perpendicular to the vertex normal?
Yeah, sorry, bevel doesn’t do this. It makes quarter circular arc in a 90-degree corner, and then transforms that arc into the angle that actually exists.
There may be some hack where you have an object with 90 degree corners where you want bevels, and the transform those corners to the angle you need with object transforms - and then don’t apply those transforms. Normally this is a no-no for bevel, but you might be able to get the desired effect that way.
There was an attempt by, I think, @HooglyBoogly a few years ago to add the option to get partial circular arcs. But my hazy memory was that, while it is all obvious what to do in flat planes, it ran into problems we couldn’t figure out how to solve in the general bevel case. Or maybe we just ran out of steam trying to figure out what do.
I am currently working on a bevel Geometry Node, so my mind is actively thinking about bevel again. I might go back to trying to add this option. But it won’t be in the initial release of the bevel geometry node (it’s going to be tight as it is to get something that is at all usable by the deadline for 5.0 beta…
Amazing Howard ! It’s great to see this being worked on ! Thanks a lot for your time and dedication ! First the manifold solver , now bevel node, you’re on fire !!
