[LibGDX] Collision with decals

Hi so I am making a “perspective” game sort of like ortho robot from Stabyourself.net
The premise of the game is there are 6 tiledmaps rendered around a 3d cube and each face has a shadow of you on it and a player. When you move as the player the shadows move and you can switch your player to the positions of the shadows and leave a shadow in your place. The idea being that you switch faces/maps of the cube to walk over things you couldn’t on a different space, switch back and call it a day. The issue at hand here is that I’m using a ModelInstance cube for the base and then taking TiledMap data (id’s) and translating them into a grid of decals rendered on each cube face, the shadows and player are decals as well. How would I test collision for decals? I cant really do rectangles considering i would get overlaps on 1 axis of all the different tile hitboxes there would be. Any help is appreciated.

Picture Below Of Game
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