Rotations-like or distortion-like corrections about x and y

[dataplane]

All the rotations are done about z axis which is perpendicular to image plane. Can't we do rotations-like or distortion-like corrections about x and y axes at a few degree angles directly or indirectly by combination of commands?

[LeviFiction]

Technically if you use the pick tool start with perspective to narrow one side, then squash the image using scale it is similar. If you absolutely need to rotate in 3D space then you need the 32-bit version and the KPT plugins one of those effects I believe allows for that.

[Andy2011]

I agree with LeviFiction that a basic rotation can be achieved with the controls in the Pick tool. If perspective is not a requirement, an object at an angle to the XY plane maps onto the plane by the cosine of the angle. For example, if a square of sides 100 pixels is rotated 30 degrees around the X axis, the length along the X axis is still 100 px but the Y dimension is 100.cos(30) = 87 px. A square maps to a rectangle and a circle to an oval.

Getting the perspective is tricky. One aid is to use a temporary layer on which there are lines drawn to the vanishing point. That provides a guide for the distortion when using the handles on the object's bounding box. Obviously the rotation is of a "2D" flat sheet (lamina) and it is another exercise to add bits to make the rotated sheet a "3D" object .

[dataplane]

@LeviFiction and @Andy2011 Thank you very much for the replies.

[LeviFiction]

I was asked to provide a better explanation of what I was talking about.

The KPT plugin is called KPT Projector - It has a 3D rotation tool. I'm including a video that shows the absolute basics of its use.

As for the Pick tool, the pick tool does not actually rotate in 3D space. It's a 2D program only. But if you can simulate the effect through a combination of perspective distortion and scaling. I also show that in the video. The important thing to keep in mind is that when you use the perspective tool it's just shrinking one edge of the image. To simulate moving in 3D space you need to shrink one edge, expand the other edge, and then bring those two edges closer together. Squishing the image corrects for the perspective distortion of the image.

While I don't make note of this in the video, always keep a duplicate copy of your original layer when working like this. Especially with KPT Projector. These are destructive edits, the more tweaking you do the more data is lost. So if you need to change the view and you've used the KPT Projector, just delete the layer, and create a new duplicate of the original layer. Then when you go back into the KPT Projector it'll remember your last used settings and you can either continue from there or start from scratch.

Here is a quick video demonstration - https://drive.google.com/open?id=1pIi42 ... 5mDGGDk6H6

[dataplane]

Thank you very much for providing the basics of the tool so nicely.