I want to do legdes and frames and wondered what the easiest way to do a mitred corner would be. Mitred corners are those 45deg but joints around picture frames etc. Currently I extrude the profile of the frame and sweep the corner with 2 steps then pull the middle verts out to keep an edge but this is fiddly.
Any ideas welcome.:rolleyes:
You could try to use curves. Make rectangle curve and then use another curve as its profile (bevOb).
You may find http://mediawiki.blender.org/index.php/Tutorials/Curves/Making_A_Tube and http://mediawiki.blender.org/index.php/Tutorials/Curves/Curve_Taper useful.
Taper is useful if you want to vary the width of beveling.
Have you tried the Bevel Center script?
Place the 3d cursor on what will become the inside corner of the mitre. Change the pivot point to cursor. Rotate the edge by 45 degrees and then scale the edge by 1.414 (the square root of 2).
GreyBeard
Overlap the two boards. Superimpose the exterior corner vertices
Move two vertices to the interior corner (G, X)
Move the other two vertices to the interior corner (G, Z)
Remove doubles (may need to increase the doubles limit)
If your boards have interesting profiles
Use a variation of Greybeard’s method: Set the cursor to the outside corner (select the corner vertices then Shift S>>Cursor to Selection), set the pivot point to 3D cursor, rotate and scale the ends of each board to meet at the joint, then remove doubles. Tips: Press CTRL and watch the ROT number while rotating to get exactly 45 degrees. Press S (scale) then type in the scale factor (1.414) instead of using the mouse.
I have made a number of frames in the past, here
is a mini tutorial of how I do it, I hope it makes sense.
Bob
OK, now that I have followed this thread for a while, it appears that I had completely missed the point with my first post.
When I create a frame that I want to have mitered, I start with a square plane. Select all verts, extrude region, then esc key. Now I have 4 new verts directly on top of the originals. Next, s key to scale down, using the ctrl key for nice increments. When finished, delete the 2 faces in the center and delete them.
The Down side to this is that it you want to scale in one direction, you wont be able to without trashing the miter. Instead, you will have to go into edit mode, then select the verts for one side and slide them along an axis.
This will only create a basic frame (no shape) to start with, but using loop cuts on one side, you can add shape to the frame.
Best of Luck!
Attachments
Wow thanks everyone for the various methods, and big thanks to Greybeard for every other piece of advice too 
I’m not infront of Blender at the moment , but isn’t there a shear function now? Can I use that to get correct 45deg mitres?
Of course there is a shear transform: Ctrl+S (also in the transform menu)
It works horizontally however, so if you want to shear vertically, rotate 90 degrees first.
Shear 45 degrees to the right: ctrl+S 1 intro
Shear 45 degrees to the left: ctrl+S -1 intro
Shear vertically to the right: R 90 intro ctrl+S -1 intro
Shear vertically to the left: R -90 intro ctrl+S 1 intro