Right size and correcting the physic ?

Hi
- My problem now is the size of some 3D models. when i load it to my project the size of this model is bigger that the my project !! so how to know the right size ? if i mad a wall how to know is long 1 mater ?
- These models are empties. i can see it but any thing walk through it. nothing stop it !! how to make this 3D model real ?

 

1. Check the export settings of you 3D app and the import settings of the model in Unity, and adjust the scales there, 1 unit in Unity is equivalent to 1 metre.
2. Add a collider to your object.

 

thank you for reply
but the first point still confuse fro me. is there any tutorial for it ?

 

What modeling program are you using?

Create a plain cube in your modeling application and export it, then import it into Unity. Check the import settings and make sure the scale is set to 1. Add it to a scene, and then add a primitive cube from Unity. If they're the same size, your two applications are using the same scale. If that's the case, you just modeled it too big. Use a basic cube in the modeling application as a measuring stick to scale your model down.