Material Not Showing And Unable to Pickup

When I spawn an entity that I set as a model I made, it is filled with purple and black checkers and it is unable to be picked up with a physgun. It also can be walked right through. The shape of the object shows though.

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EDIT: After looking around, it looks like I’m missing a collision model. How would I get/make one of those?

EDIT 2: I was able to do this myself. I made a rough redo of the model as my collision model and added a VMT and now everything works fine.