Physics Or Collisions

Q: Actually I’ve imported a mesh(ground) as shown in the below picture and I would like enable the collisions for the imported mesh.As i’ve integrated various meshes in the imported mesh with some tool.And now my issue is, how to make my character do not to move through imported mesh where various kinds of meshes are integrated.As you can see in the below picture.

Please help me to solve this.
Thanking you

Hey this doc could be helpful:
Introduction to Developing a System For Collisions | Babylon.js Documentation


Thank You @Deltakosh