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I am making a tire. The treads on the left and right side of the tire need to be offset from each other, ie, rotated about 10 degrees.
Is there a way to rotate the result of a mirror modifier? I tried using an array modifier with the array object being an "empty" that is scaled -100%, but the result is an inverted side.

Here is the half I have: enter image description here

Here's the mirror result: enter image description here

And here's how I want the mirrored portion to be rotated: enter image description here

The way I produced this result was by applying my modifiers, but I need to be able to rotate the mirrored half without applying, if possible.

EDIT: I thought I was onto something when I realized that you can mirror using a "mirror object", and the mirrored half will rotate when you rotate the mirror object, HOWEVER, it will only rotate in the other two axis: If I mirror over the X axis, I can only rotate the resulting half on the Z and Y axis. Seems like that should be an update to the feature.

EDIT 12-22-15: My workaround:

What I hoped to accomplish was to model an entire tire by simply only making the mesh for 1 tread on 1 half of the tire and using modifiers for the rest. That doesn't seem doable. For now at least, I modeled 2 treads, 1 on both sides of the tire, and will array that. enter image description here enter image description here

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    $\begingroup$ Please add some images to your question to illustrate both the problem and preferably the desired result. It is a little unclear from just your description as to what you want. $\endgroup$ – Ray Mairlot Dec 21 '15 at 17:36
  • $\begingroup$ I will add pictures now... $\endgroup$ – Ben Mora Dec 21 '15 at 19:11
  • $\begingroup$ I'm curious to know what your purpose is. I needed tires of particular sizes (the one pictured is a 385 95R25, and I also need another slightly larger tire for models of heavy construction equipment. I decided this was a good project to use to improve my knowledge of modifiers, in particular, the array modifier). Is this the case with you, too, Ben? Otherwise, I'm wondering what is wrong with the blend in the third image edited into your post? $\endgroup$ – brasshat Dec 22 '15 at 3:11
  • $\begingroup$ There's nothing wrong with the one I produced in the third image as far as the end-result goes, but I am preferring to use modifiers without "applying" them, which is what I had to do to get that result. I am asking primarily because I know there are always better or more creative ways to do things, and I think if I can use modifiers to make a truly uniform and symmetrical tire, it would be the most efficient and least destructive method, but would also be useful information for future use on who knows what else. I will edit the original post to show my work-around. $\endgroup$ – Ben Mora Dec 22 '15 at 13:40
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I figured out that you actually can rotate the result of a mirror modifier by using and rotating a "Mirror Object" , however you can not rotate in the same axis that you mirrored across. For instance, I have modeled half of a tire... enter image description here

...and mirrored it across the X axis using an "empty" as the "Mirror Object": enter image description here

At this point you may rotate the Mirror Object on either the Z axis... enter image description here

...or the Y axis... enter image description here

...but not the X axis, since that is the axis used for the mirror modifier. The same holds true if I was to mirror across the Z axis, I would be able to rotate in the X or Y axis, but not the Z axis. I thought I could be tricky and mirror over the Z or Y axis and use a combination of the other two eligible axis to create the rotation of the mirrored half that I desire, but alas, it is not possible to arrive at the desired rotation like this: enter image description here *Note, the above is my workaround where I had to apply the mirror modifier before rotating it manually.

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Ben, no the mirror modifier only produces symmetry across a plane; there is no way to rotate. One approach I used to model a tire was to model a strip across the entire width of the tire, and use an array modifier around an empty to arrange the instances of the array around the center point. The bit of the tread I modeled is outlined in white.

enter image description here.

I should note that I only modeled the raised parts of the tread, and not the side wall or base; these were a separate object.

This technique worked, but the results were unsatisfactory because I was modeling a real tire, and it turned out that the different strips around the tread did not have the same size; the left three parts of the thread occupied a smaller part of the radius (1/48th of the radius, as I recall) than the right two parts (1/40th of the radius), so what I wound up doing is modeling the tread pattern as two different bits, the three left in on bit, the two right in the other, and applying the two different segments around the body (the sidewalls, and base of the tread), as in the illustration, where I've rotated the tire body, and highlighted the two segment arrayed object for illustrative purposes.

enter image description here

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  • $\begingroup$ I'm trying to use the mirror modifier to keep both sides symmetrical (and editable). I am already modeling 1 strip of the tire and making an array all the way around for half of the tire, at which point I am mirroring the whole array for the other half. $\endgroup$ – Ben Mora Dec 21 '15 at 22:05
  • $\begingroup$ Well, the mirror modifier will keep both sides symmetrical across the plane, but only one side will be editable. If you want to edit both sides of the tire, you can do so after applying the mirror modifier. $\endgroup$ – brasshat Dec 22 '15 at 4:45

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