Shear Tool

[clintonman]

I've been learning a little Blender and found this tip.
https://www.youtube.com/watch?v=akEVVY87SmA
Extrude at a 90 degree angle

That's the first time I've seen shear used in a useful way. So I'm starting a new tool for tS. The images shows the first test.

From left to right is
1) vertex selection
2) shear -1 in Z
3) dynamic sweep with an offset close to zero then moved up in Z
4) scale selection to zero to flatten it.

The code is attached but is no where near a usable state. It's only a test.

[clintonman]

ShearToolUI.jpg (29.59 KiB) Viewed 701 times

New approach makes more sense.
The trueSpace matrix shear values don't make any sense to me. I found some math for 3D shearing transforms here:
https://lnct.ac.in/wp-content/uploads/2 ... EARING.pdf

I copied that math and now it makes sense.

These are the steps for the image above:
set ShearX to -1.0
select the ShearZ radio button
select the face pointing in the X direction and run the tool

The result is the further a point is away from the object Z, the more it moves in the X direction. Selecting ShearZ means the Z value does not change and setting the value of -1 in the ShearX number will move the points in the X direction to form a 45 degree angle. If a ShearY value was set the points would also move in the Y direction.

If the origin was at the bottom of the box only the top selected points would move.

The current status is that the tool works properly. The next step is to try making it more user friendly.

[trueBlue]

Have you tried the Blender Shear tool that includes a widget?
https://www.youtube.com/watch?v=N8O0bE898Qc

[clintonman]

Have you tried the Blender Shear tool that includes a widget?
https://www.youtube.com/watch?v=N8O0bE898Qc

Nope, I knew about the shear shortcut, not the shear tool with widgets. Thanks for the tip.

[clintonman]

I started working on the widget for the shear tool. The proof of concept is shown above. The usage steps would be this:

1. Make a selection and start the tool

2. Choose an axis to lock via the spheres on the arrows

3. It will default with the shear at the center at the selection, you can see the orange center indicator in the image.

4. if needed change the center - The colored dots will set the center to the bounding box faces of the selection. S will set the selection as the center and O will set mesh origin as the center

5 drag on one of the arrows to do the shear.