rooms definitions: arx textures sometimes have 4 subtextures

[meszaros-lajos-gyorgy]

The following fabric textures are indeed 4 separate textures in one:

The goal would be to not just be able to use the subtexture on one quad, but to have it tiled on a large surface. That might require some custom UV mapping code for ThreeJS plane.

Probably the following part can be done separately later, but some textures don't divide up the image file into equal parts: