Have a look at the inspector tool bar under the gripper bit. You can select centre of part you pick, or user position and all this. Might be what you're looking for?

Thanks for the replies.

No, that is to place the gripper. I want to reset the rotation point of Dynamic rotate. When I select 'Centre of selected' in the Inspector/Gripper, the place of the Gripper changes.

But it will still rotate around the object that I Option-clicked. That means when I zoom into an object without selecting it, I can't rotate, as it will rotate around an object outside of the viewable area, that has previous been Option-clicked.

Ah, there is some confusion. I don't want to rotate the part, I want to rotate around the part. The Gripper has really nothing to do with this, but I now understand why the comments refer to the gripper. It's about rotating around the object that is in the middle of the screen. Not rotating around a point outside of the screen.

Try this:
1. Take a cube.
2. Zoom in until you it fills about 70% of your screen.
3. Choose Dynamic Rotate tool.
4. Option-click on the cube on the left edge.
5. Move half of the cube outside the left part of the window, so you only see the right half.
6. Try to rotate with the Dynamic rotate tool

Result:
You will not be able to rotate the cube, only move it up and down, as it rotates around a point outside of the centre. Only by Option-clicking the right side, you can rotate again.

Before using option-click, starting with a fresh loaded Viacad, you would have been able to rotate everything that is in the middle of the screen. As the rotation middle point is not fixed on one point, but will change to around the middle of the screen.

So how do I cancel the selected rotation point?

Hope this is clear.

Please forget about the Gripper. I don't want to move the object. I want to move around the object, to approach it from another side. I'll do a video.

Video of the issue: https://youtu.be/a6r6_Td6keI

Nope. That is not my issue. If I wanted to move the object in view again, I would just hold the space bar to move the whole thing.

You see near the end I can't rotate the object. Only up and down, but it won't spin horizontally. That is because rotating around the object, the centre point, is set at the most right point of the object. It is too far away from my cursor to rotate around. I'm pulling on the outer edge of the object. But if you hadn't done option-click, you could actually spin around the object on the horizontal axis.

Have you tried to option-click on different places around your object and then experience the difference when you rotate using the Dynamic Rotation tool? It seems you don't understand this function. It is explained in the top bar. But it doesn't say how to cancel it.

I think the function you were looking for to get everything in the screen again is Zoom All. Short cut = E

Hm, no, it has nothing to do with field of view. With all respect, it seems to me you don't understand what this option-click function does.

The question should be simple for someone who knows the function of Option-click with the Dynamic rotate tool: how to cancel this and go back to default, as it is when starting up.

Anyway, I've emailed Tim. Hopefully he will respond with the answer. Maybe it is just not possible to revert the action.