Add collider to a 3D model

I created a model in a 3D modeling software and imported this in Unity. Now I would like to use a collider function in order to set boundaries for the range of movement of this model. Is this possible with an imported model of a 3D modeling software? If yes, how?

Thank you for your help.

See attached the image of my model (ring). The aim would be to enable a movement within the range of the the ring. [65544-ring.pdf|65544]

Mesh Collider is what you want to use. However it depends on how accurate you need the collision mesh to be and how many of these objects are going to be in your scene. Your torus is quite high poly so using it as the collision mesh is going to be pretty costly and inefficient, especially if you use this object multiple times.

Your best bet is to also export a lower poly version of the mesh to be used as the collider for the high poly torus. Just assign it as the mesh under your mesh collider.

Also, whilst I am here… you don’t seem to have exported the smoothing groups which is why your torus surface is all tessellated like that. Unless that look is intentional, you should select all faces of your shape and set them to smoothing group 1 and make sure the smoothing groups option is checked when you export the mesh. In some software you will need to manually convert it to an editable mesh before exporting or it will lose the smoothing groups.

Smoothing it will also allow you to get away with a lower poly mesh without it looking ugly - currently your torus is probably far higher poly than you actually need.