Cutting cylinders at an angle

I’m modeling a log home and need to cut the logs at an angle that matches the slope of the roof. I’ve googled this and have seen an answer or two related to solid tools (pro) and using a section plane to achieve this. A section plane is supposed to be used to cut the logs at the roof’s angle by intersecting(?) it with the logs and then deleting the excess log. All I manage to do is to remove the logs or add a sheet-like rectangle to the model.

I was hoping someone would have a more clear instruction to do this. Please use small words as I’m a little dense at times. :wink:


Don’t use a cutting plane–that doesn’t actually alter the geometry.

You want to use the Intersect Faces command. Pass a face ( a rectangle) through a log where you want the cut. Then select the face of the rectangle, right-click > Intersect Faces with Model. Then clean up excess geometry.


Cutting Plane

This shows what Gully describes.

Add the detail in what both Gully and Dave describe that if the geometry you want to cut is a Group or Component, you should first cut (erase) the face, then open the Group/CI for edit, paste-in-place, and then do the intersect. Otherwise the intersection edges will be in the general model context whereas the faces you want to cut will be inside the Group where they can’t be affected by the new edges.

You can use Zorro2 to change this.

Another way if you know the manual steps and want to speed up the process…

Thank you very much. I realized why it wouldn’t let me intersect after trying what you folks told me to do. All of my logs were individual groups. The only way it would let me intersect and then erase the unwanted geometry was to explode all of the logs I wanted to intersect with the plane. With everything exploded it let me do the intersection, deletion and then to re-group.

Thanks again.

That’s one way to do it but you don’t have to explode them to make the intersections properly. Exploding them and remaking them is just additional work.

Actually, Steve, as long as you (the camera) are inside the component’s context, the cutting face does not have to be. The lines of intersection always appear in the current context, so if you get into the component context, select all, then click Intersect Faces with Model, the external face will cut (create intersection lines) inside the component.


You are quite right, the crucial part is to have the context open where you want the cutting edges to occur. Though when you intersect with model you have to be aware that it means “all of model”, which could accidentally catch more than just the cutting face!

I think my issue could have been that I was trying to cut multiple groups (logs) all at the same time. I think I’m going to need to watch a ton more tutorials. :slight_smile: Thanks again.

Another option that might be worth considering is to cut one, copy it to the other positions and modify then to make the rest. In this example I just selected the ends and use the Move tool to stretch the logs.

Zorro, as mentioned above, is a very handy way to deal with this sort of thing.