I've been building some virtual furniture for a job. I have yet to come up with a clean way to cut a forty-five degree angle in the trim, whick should fit together seamlessly. So. I open a vertex modeller, make the shape of the trim and extrude it a few times. Then I select the vertex I want to rotate around, one of the end ones. I notice that 'shift to constrain' to one axis doesn't seem to apply here. I get unwanted rotations on the other axes, getting minor twisting of the object, kinda like a peice of licorice candy. Also, I get shrinking of the end of the object, unwanted. I re-size to get the end 45 degree angle as close as hand and eye allow. Help!

D., Looks like your Rotation point is set at the wrong point. The point of rotation should be set at the vertex where you want the rotation to take place. The Cyan color shows the vertex where rotation should take place. CTRL-ALT-Click on that vertice and it will reset the axes. Now this means that the vertices being rotated will rotate in the correct angle, but not that they will spread out to make it perfect in line. That would require you to resize the spacing of the vertices along the X and Y axes. It will definitely take some doing, but it CAN be accomplished. For a quick fix, use a standard 5x5x5 block set at 45 degree rotation on the Z axis and boolean it out of the moulding. It may create a few extra vertices, but it would solve your problem and create a straight edge. Ken 

Hello deedub, Here's the "gotcha": the 45 degree angle is actually wider than the original cross section. The 45 Degree cut means that there is more wood to cut through because of the angle. How much wider? I don't care. I let the spline modeler do the thinking for me. 1. create a cross section, also select the last point on the pre-existing extrusion path and choose 'create cross section' from the pull down menu 2. select "pipeline" from the extrusion method pull down menu, 3. draw the path you want the cross section to follow. Sometimes the corners 'balloon' and get wider than they should. 1. under the extrusion envelope method, choose 'symmetrical in plan", grab the points on the corners and drag them back into alignment. Hope this helps. Mark

Another quick way to get clean mitered corners is to center your cross section in the SM, then apply the torus preset. Use the point convert tool to change the 4 points of the torus path to corner points. If you only need sections and not a complete frame you can send it to the vm for cutting and setting section lenghts. mdc guam usa

The cross section width of a 45% angle is 141.43% larger than a 90 degree. Therefore to end up with the correct width you have to increase the width of the end by 141.43% and then rotate 45 degrees. Keith

Man, this is too cool. Tomorrow's workday will be a workthrough of all your solutions.
Thanks, guys...This beats the th!T out of manuals.

I'm attempting MaarkBremmer's spline technique first, then I'll combine cckens Nd Kieth's suggestions. I do a quick textured render after each one, to see if there are distortions like I'm getting in thre project. Here's what three tries at Mark's spline technique have yielded...almost there. If you're around today, Mark, where'd I go wrong? Deedub

Mark: Perhaps there's something I misunderstand about the translation envelope: deedub

whkguamusa: Squaring off a toreus sounds like it should work: I got distortion on the top of the 'square torus'. I'll take it into the VM as you suggest and delete the top half. Might work.

MDC not going to recommend Amapi?

Brian, aside from the topic being "carpentry in Carrara?", it would be too easy in Amapi. :>) 1. draw trim profile 2. freehand sweep (center icon for regular sweep option) or click on any curve on the screen that will serve as the path. 3. Done 4. If you wanted to you could go back and pull any point in the path and the profile will move with it, keeping the shape correct. Each point also as a small scale handle that you can interactively pull to scale the profile, at that point, from the center out. It is very much like doing it in the spline modeler except no distortion problems & you are not tied down to any working/drawing plane. 5. Now if you want to build the trim to tolerances of .0001" and end up with a file that would go directly to a CNC milling machine ask me how to do it in Rhino. mdc

So. Guys, thanks. Ken: I never was able to get the placement of the rotation point (ie: vertex) to jibe with the rotation axis, x,y,or z. Odd things, like a section shooting off seemingly to infinity were happening. I'm nervous of how booleans affect texture consistency. Mark: Success: I made the 45 degree bend with a circle extruded so I could see the effects of my changes. I had success with the 'free' extension envelope, tweeking them all slowly, bit by bit. Did a 'create section' for each end and the corner. Deleted the circles one by one, pasting my shape in and centering it as I did, Looks like a nice clean, sharp object. mdcguamusa: No luck with the torus...turned into a weird object when I took it into the vertex modeller. Took textures poorly. Missed something, I guess. Kieth: Since I never was able to plant the rotation axis on a vertex that worked, no success with your size ratio, which appears to be dead on accurate. (141.43)

Here's the circle extrusion with shapes pasted in. dw

MDC: Here's the torus result. I have Amapi, looks like I oughtta use it. (Learn how to...) Distorted badly when I re-sized it. Couldn't figure hoe to 'fill' the end caps. dw

Finally, before I stop beating a dead horse, here's how it distorted in the vertex modeller. dw

From the Beating a dead torus dept: All in all I don't think that this is a great way to make this if don't need a closed frame. But to get one without distortion make sure your profile shape is grouped and centered before applying the torus preset. Don't set any envelope options.Create a cross section at each of the points on the path before converting them. It looks good then, but I can't find a way to open the closed path so that you wouldn't need to go into the vm for further editing. It seemed like I was able to do this before in rds but I don't model much in Carrara any more. It is easy to select the open edges in the vm and fill the polygons. You still have the mapping problems that come with using the vm, so it's a wash. mdc

Thanks again for your suggestions. It's all learning for me. ...dw

If I'm whining, tell me to shaddap! Is there a way to assess the size of an object as you model it in the spline modeller? Here's the challenge: when you re-size a spline object in the assembly room, even in just one axis, you lose those hard won 45 degree angles. I'm making a cabinet according to a drawing from the client. It has trim on the top that's just like the baseboard in the average home. the joint on the corner is in full sight and must be clean-looking. The Objects must take clean (natural wood) texture (from Tiled Textures dot com.) Re-sizing the trim ruins the 45 degree angles, as in the attached drawing. Help! deedub (David.)

Ok here's another clubby solution. Figure 1 shows the starting spline object with just the generic shape that we want. This is going to be a pipeline object. Figure 2 shows how I've changed the sweep path to have a perfect 45 degree in it by adding another point and moving the end point. Figure 3 shows how I've changed the envelope by switching to "free" and moving the two ends into a straight path. Figure 4 shows that I did this with the other end by adding a point, making it a cross section, and then repeating what I did with the other end. Figure 5 shows how this gets distorted in the vertical plane so I fixed that up as well into figure 6. Next post please.

So now I have a piece with perfect 45's in it. If I wanted them to be longer, I'd select the two end points along the sweep path and move them at the same time. The image shows two of these pieces butted up together at the ends. The lightsaber tutorial in the backroom uses this technique somewhat as well. -Kix

Kix:
Man, I'm going to have to do a lot of experimenting with the spline modeller. After a couple of attempts, I was able to follow your tut. and make a right-ended forty-five. Thanks! I didn't manage to do the other end, mainly because I couldn't get around the way there seems to be a constraint on the first point on the (purple) sweep path... move one, you move them all...even in 'envelope:free'. Once again, I'm missing something. I'm embarrased to say I've not checked out the back room yet. I'll go there and do the lightsabre tut.
...dw

See the second point along the sweep path in figure 4? Make that a cross section and then you can proceed. -Kix

Kix: Besides a thankyou, I need to express a thought here: if folks like you, who share their time and knowledge just out of their common interest in 3D are in this world, that's gotta make it a better place. Thanks. ...dw

Thanks again for all the support. ...dw

You're welcome and thanks to everybody who pitched in on this one. Excellent comments and ideas! -Kix