Hello !

A few months ago I painted a cylindrical rock tower, and to gain some time I wanted to deform a rock wall texture so that it followed the shape of an imaginary cylinder but it was quite tedious and kind of imprecise to do it with the warp tool, so I'm wondering if there is maybe a better and faster way to warp a texture "around a cylinder" in Krita and if someone would be kind enough to give me some advice about it.

Have a great day !

The GMIC filters have a Deformations section that has a Conformal Map deforming filter. Among the Mapping options there is the Custom Formula option which should do something close if you can work out the formula required. That would require some serious internet searching or someone may know what it is, if you're lucky.

Alternatively, this sounds like a job for Blender and there's probably a YouTube video that shows you how to do it.

ahabgreybeard wrote:The GMIC filters have a Deformations section that has a Conformal Map deforming filter. Among the Mapping options there is the Custom Formula option which should do something close if you can work out the formula required. That would require some serious internet searching or someone may know what it is, if you're lucky.

Alternatively, this sounds like a job for Blender and there's probably a YouTube video that shows you how to do it.

Hello, thanks for your quick reply !
Well I just want to gain some time by quickly deforming a texture to make it look like it's wrapped around a cylinder by mimicking the way it's almost not deformed where it's facing the spectator and look more and more compressed the closer you get to the "sides", so the whole point of my request is to get a convincing result quickly and intuitively without using a 3D software or coming up with a complicated formula ^^'
I agree Blender and other 3D software could really wrap a texture around a cylinder, but It's not exactly what I am looking for and that would force me to think about the lighting of the 3D scene, the material of the cylinder so it doesn't reflect light in a weird way, the camera placement, etc... just to get a usable snapshot... ^^' and for GMIC Filters, it's even more complicated and force to come up with a complicated formula

Currently it's doable with the warp tool, but it's looooong (because when you subdivide your texture horizontally it also subdivide it vertically even if you don't want that behavior, and after that you have to select every anchor point you want to move 1 by 1 because you can't select every point in a rectangle for example) and it's kind of imprecise too, so I'm looking for a better way to do it ! ^^

Considering it more closely, the custom Conformal Map is totally hairy and the Cartesian Transform should be able to do it but with a tricky formula for X-Warping (with Y-Warping set to 1). The Spherise deformation could give a reasonable approximation if you stretch the circle vertically (i.e. Ratio slider, to minimise vertical scaling distortion) and choose the other variables carefully. If you put your texture image in the middle of a larger plain background, that would help to reduce edge effects as well as vertical distortion. That's all else I can think of so good luck with it

Thanks again ! I just tried the Spherize deformation, it can work in a 1-point perspective if the vanishing point is in the middle of the tower, but it wouldn't work in any other case I think ^^' so I'm still looking for a more universal and easy to use solution ^^