3D Bezier Bevel

Can’t get good geometry in sharp joints in 3D bezier curves

Can get it in 2D, but i need 3D to make turns in another directions to make things like this

Solution 1:
When bevel object symmetrical on X and Y axes (circle or square for example) i even can fix this by setting control point radius to something like 1.33, but when bevel object has different height and width setting control point radius gives me unwanted thickening on axis, orthogonal to turn plane, so this method not suitable for my situations.

Solution 2:
Convert to mesh and manually connect edges in that point.
But, i don’t want to use that, because often happens that I must change something in bevel contour.

Solution 3:
Use few 2D beziers << may be this can help me if anyone tell me how i can auto-merge vertices of side by side curve objects like in array and mirror modifiers.

But anyway i ask someone to tell me how to fix this problem in 3D curves, please

I believe the bevel profile object center follows the path curve. And so if you have the bevel object center at wrong place it will fold up like that. Play with the location of bevel object center.

what happens with different center locations


Try putting the center at the tip of the bevel profile to the left.

and blend file

also can you change the bevel size
it looks to me like it is very big compared to the radius of curvature of you main curve meaning more distortion!

also i can see some tilt problem on some points !


I can change the bevel size, but if i change it i get too tiny object and anyway distortions also will be!
I just seeking a way to make things i exactly need instead of making things than i already can make =)

then try to add more points in the corner but it will add on vertex count!


I’m also experiencing this problem. It’s really handy to be able to use curves to make things like skirting boards, but once you need a skirting board that goes up or down, then the nightmare begins :).

Any info on this?

Hey, this is kinda important imho. Call the devs! :smiley:

can you show some pic or upload a sampel file so we can check it out
and recommends some changes!


A mesh based alternative would be zmj’s extrude along path script!

@RickyBlender: Aren’t the pictures already posted enough? I don’t think it’s necessary a sample, it’s very easy to reproduce the issue, add a bezier circle and a b. curve, select the curve and on the bevel object select the circle, convert the handles to vector and extrude one of them making an approximate 90º curve. At this point you can switch between 3D and 2D modes and see the difference.

@PyroGXPilot: I’m gonna check it out. Thanks.

don’t know waht prolbme he has
would like to see sample file to analyse it and see what the best way is to do it!


Yes, I can reproduce this. The interpolation changes when switching between 2d and 3d splines: a work-around for simpler splines it to set the active spline’s U-resolution to 1, and then select the 90deg corner point and increase the radius for that point a bit to counter the change in size.

Not perfect, though, and only works for the lowest U-resolution. Adding a sub-d modifier rounds the corner again, so - and we cannot set the bevel weight for that corner point (which would be handy, btw).

I wouldn’t necessarily call this a bug, but the expected behaviour is different.

I think this is a bug. Specially if you need vector- or free handles for sharp corners, the original bevel profile turns correct, but the “profile diameter” is unchanged. This destroys the corner area and makes this tool quite unusable in those cases. If i could, i would do the bug report. But i can´t. So please do it for me.
(If i remember correct, this tool is operated properly in some earlier version, maybe in 2.49b)

I don’t know if this tool used to work correctly in 3D mode, but scaling the node doesn’t work because it scales in all directions, while the curve gets deformed only in one.
Uncool man, uncool stuff :).

It never did. Had the glitch in 2.4x, so it was just somehow overlooked.