Can't get Boolean operators to work with polygon objects extruded from imported splines

Chris Heath

Chris Heath

0
Hi I'm getting the hang of importing splines now, however I have a new problem. The Boolean operators do not work with polygon objects that are made from extruded splines that have been imported. Is this a bug? For now I'll work around it using a cheetah cylinder and I'll trace the hyperbola shape using Cheetah's spline tool. I've attached my file and a link to a video that explains what the problem is. Thanks in advance for your help with this.

Video Link on Vimeo
 

Attachments

  • Boolean with Imported Splines Extruded.zip
    19.5 KB · Views: 45
Can‘t look into the file right now - but my guess is the „splines“ are not closed or contain double nodes. Or you need to optimize the mesh to make it watertight.
 
frank beckmann said:
Can‘t look into the file right now - but my guess is the „splines“ are not closed or contain double nodes. Or you need to optimize the mesh to make it watertight.
Click to expand...
Hi Frank.

The circle spline is a standard Affinity Designer circle shape. The hyperbola curve was initially open, but I fixed that and reimported it. I just rechecked the nodes and they all appear fine: The hyperbola shape is closed and there are no double ups that I can see.

Update: I have made them both editable and optimised them. Now it's all working (I had tried these before, but I think that was when the hyperbola spline was not closed and had a double up of points) The only glitch is the purple column has inherited the blue colour, but I'll ignore that glitch.

Thanks again Frank.
Boolean working now WB.jpg
 
Last edited:
frank beckmann said:
I can still perceive a small weakness in the Hyperbola spline when you change the Type: to the other 3 kinds.
BTW - drawing the Hyperbola in C3D from a 4 node circle spline is easy:
Click to expand...
After seeing what Eric is doing, and now this, it looks like I need to master C3D splines. To reproduce the shape from a 4-node circle, did you use the imported shape as a reference, or was there a geometric method that you used?
 
I took your spline as reference and worked in your file. Steps are easy:
1. Call for Circle Spline - make editable
2. Enable snapping to raster and drag East und West nodes to left resp. right.
3. Select East/West nodes and go Spline->Hard Interpolation
4. Select North/South nodes with shift and scale vertically till they meet your reference
5. Select the 2 East/West nodes and scale them vertically till they line up
(6. I selected the 2 North/South nodes and scale them horizontally a very tiny bit) - Done
Hyperbola.jpg



Just a small hint for none symmetrical shapes: we can select node handles with key shift down and scale/alter the curvature as a hole or with cmd-key down just from the nodes:
AlterSplineHandles.gif
 
Last edited:
frank beckmann said:
I took your spline as reference and worked in your file. Steps are easy:
1. Call for Circle Spline - make editable
2. Enable snapping to raster and drag East und West nodes to left resp. right.
3. Select East/West nodes and go Spline->Hard Interpolation
4. Select North/South nodes with shift and scale vertically till they meet your reference
5. Select the 2 East/West nodes and scale them vertically till they line up
(6. I selected the 2 North/South nodes and scale them horizontally a very tiny bit) - Done
Click to expand...
This is awesome, thanks Frank.
Cheers
Chris
 
Another way to define a parabolic curve is with a cone.
After all a parabolic curve is a Conic Section parallel to a cone's wall.

Then you can use Master Hiroto's PolygonToSpline script to extract a Spline if you want.

Parabolic conic section.jpg
 
You must log in or register to reply here.
Back
Top