Does Panda3d support portals? I was going to use Godot since it has built in IDE but I looked up portals and they have to fake it because Godot doesn’t support Stenciling and custom projection matrices which hasn’t gone anywhere since 17.
Do you mean portals as in portal culling? There’s a sample program for that.
Or do you mean portals like in the game Portal? Yes, you can do that in Panda3D. The best way I think to do that would be to set a StencilAttrib that sets a bit in the stencil buffer when rendering the portals, and then, in a new display region, render the scene again, but with a clip plane and a special stencil attribute applied, and from a different angle.
An alternative method is to use render-to-texture. I believe that this method is demonstrated in the example you showed.