Render Shadow of a Model on Any Background Pic or Image using Matte Shadow Reflection Mental Ray

Every 3d artist wants to make his renders as realistic as possible.

One of the basic criteria to make your 3d model photorealistic is to try and match the environment background with the model.

Just adding a hq background to your render without any shadows makes the render very unrealistic.

So following these easy steps you can easily convert any simple plain background image into a 3d environment.

Requirement:

1. Autodesk 3ds max.

2. A background image to render shadow over it.

3. Basic 3d max knowledge.

Step 1:- [ Assigning the Renderer ]

1. Open Autodesk 3ds max on your computer.
2.  Open render setup by pressing F10.
3. In the Common tab Scroll down and open assign renderer tab.
4. In production select your renderer as mental ray.

Step 2:- [ Setting up the scene ]

1. Insert or create any 3d model ( in my case a teapot )
2. Just below the model create a plane.

Step 3:- [ creating the lights ]

1. Create a mr Sky Portal light by clicking on the create tab in the Menu bar then follow this sequence create- Lights- Photometric Lights- mr Sky Portal.
2. Make sure its pointer points towards your model.
3. Make sure that the light is selected and then go to the modify panel.
4. Maximize advanced parameters tab and select color source as custom.

Step 4:- [ setting the background image ]

1. Open the environment and effects dialog box by pressing 8 or follow the sequence rendering- environment…
2.  Click on the button which says none.
3. Scroll down and select environment/background switcher.

Step 5:- [ Setting up materials ]

1. Press M to open material editor.
2. Now drag the environment/background switcher from the environment and effects dialog box to any of the material slots and select instance.
3. Select the material slot.
4. Click on the square box next to background.
5. And select environment/background camera map.
6. Then click on browse and select your desired background image.
   
7. Now click on goto parent and copy the background map.
8. Now select another material slot.
9. Assign a matte/shadow/ reflection material to it.
10.  Paste the background to camera mapped background.
11. At last drag this material to assign it to  the plane you created.

fig 5.g

5.i

Step 6:- [ Rendering ]

      a. Press Shift+Q to render the scene.