The filter "Map to Object" creates unrealistic distortions
Environment/Versions
- GIMP version:
- Package: 2.10.32 R1
- Operating System: Windows 10
I recently stumbled upon the behavior of the filter "Map to Object", which seems to be concepted in a wrong way, I think. Whatever settings you choose, the image you try to map to a sphere will be distorted on the initial X-Axis only. No matter if it is moved to the top, right left, bottom, bottom right/left, top right/left... This can't be logical, I think. I tried to document in screenshots what I mean, made some sketches to show how it should be in my opinion, and attached them to my bug report. In my example, I tried to create a billard ball. Description of the bug
Reproduction
Is the bug reproducible?
Reproduction steps:
- Create a square document;
- fill the background layer with black color;
- create a circle selection in the center of the document, fill it with white color and deselect;
- open the filter "Map to Object", select "Sphere" as object and adjust any "Rotation" you want. Then click "OK".
- As a result, the image you mapped to the object will always be distorted on the initial X-Axis, so it will have become wider, but never higher. Even without any Rotation. That is not realistic. By the way, it is the same with the "3D Image Object" filter in G'MIC.
Expected result: Take a look at my second attached illustration. The first sketch on the left shows how the image should be distorted with no Rotation at all. The others show how it should be distorted with Rotation. The blue guidelines show the target position of the image. The illustration is not absolutely accurate, but I hope it shows what I mean. I don't really know how to compute this correctly, so I tried to visualize it approximately.
Actual result: a distortion in wrong perspective.
Additional information
If you have a backtrace for a crash or a warning, paste it here.
Edited by Aviator