Hi, I’m using 3D drawings to create canvas covers. With use of a flattening tool I export it to DXF file and straight to a XY plotter. This time I’m struggeling to make the cover fair. Is there an easy fix to make this work?
Trekk til ratt.skp (240.8 KB)
One thing you should do first is correct the face orientation. There should be no exposed blue back faces. That and softeneing the edges will help.
Yours is on the left, here. On the right is my rework of your volume. I redrew the large arc with 26 segments so that with the two vertical edges on the large end, there would be the same number of edges as the small end.
This allows for a neater stitching to create the surface.
Does that do what you want?
Trekk til ratt DR.skp (177.6 KB)
Thanks! I should read more. Not sure about orienting faces and softening edges. But I’m pretty sure I will find lot’s here about this.
Do you use “weld edges” to make the outer lines in one piece? If so, how do you then set the amount of segments?
Faces have fronts and backs. the fronts in your model are a light gray while the backs are blue. In a 3D shape all of the back faces should be toward the inside. (Think about a fabric that has a different appearance on the inside and outside.) As for softening edges, it is used to graphically make a surface look curved despite being made of flat faces. The surfaces won’t really be less flat but the resulting shading make them look like they are. Compare to hiding those edges instead.
I did weld the edges after I redrew the large arc but I did that only to make it easier to select the edges for creating the skin. I select the edges on the narrow side to see how many there are. Then I set the number of sides for the large arc to that number minus two (for the two vertical edges.) This was done immediately after selecting the Two-point Arc tool and before starting to draw the arc. Get the tool and look at the Measurements window.
As for skinning, I used Curviloft by Fredo6. It’s not free but it’s very fast and gives nice results.
Thanks again for teaching. I searched for this extension, but can’t find it. I found Fredo6 but not Curviloft.
Which flattening tool do you use? Is there a prefered extension to use?
You’re quite welcome.
Curviloft and all of Fredo6’s extensions are available from Sketchucation.
Note the listed dependencies. LibFredo6 and the Sketchucation ExtensionStore. If you install the ExtensionStore tool you can use it to serach for and install extensions from Sketchucation.
I used Unwrap and Flatten which is available from the Extension Store. There’s another one called Flattery but Unwrap and Flatten seems to do a pretty good job in most instances.
Just a note on this whole idea, keep in mind that SketchUp is approximating curved surfaces by connecting a bunch of flat surfaces. Kind of like what you are trying to do with your boat cover or what you’d do in stitching up a sail except there’s no stretching faces to deform them in SketchUp. You can improve the curves by using smaller panels and increasing the number of edges used to make curves making each panel (face) smaller. there’s a point of dimishing return, though. Don’t go too crazy on the number of segments in the curves.