1. Start your version of 3d studio max.

2. Load your model.

3. open material editor.

4. Click on button named "Standard" to Create new Matte/Shadow material. Click on Matte/Shadow twice and your material will now be matte/Shadow --> what you need.

5. It is very important that you uncheck "Opaque Alpha" and check "Receive Shadows".

6. Now create new box just underneeth your model. make sure that all your shadows are dropping on that box... render couple of times to make sure.

7. Select Box.

8. Apply Matte/Shadow material to box by using this button.

9. Now render and you should get something like this.

10. it is your choice if you want to add a background. it makes your image to look like it is part of that background. see for your self.

11. Go to rendering>Environment...

12. Click on "Use map" to check it. Now select from your computer background you want.

13. and for end you must adjust position of your model to look realistic and offcourse you need to adjust lighting.