Multipass rendering in 3dsmax

When you render your scene in passes it gives you the flexibility to modify the elements in the scene. You can adjust shadows, lights , specular , reflections anytime in a compositing software as per your need.

Basic Render Elements

Ambient Occlusion – This is not a pass but a shader which can be included as a pass. Use this shader to get contact shadows.

Diffuse pass – It is the flat renders of all colors in the scene. It contains only textures.

 

Lighting pass – It renders only direct and indirect lighting. Key light , fill light , rim light are rendered in different passes.

Reflections pass – It renders the reflections in the scene.

Self illumination pass – It renders the self illuminating materials in the scene.

Specular pass – The specular component of rendering. Can be additionally used for blooming.

Matte – Perfect black and white images can be used for masking.

Z-depth pass – It is used for depth of field and color saturation based on depth.

 

Setting up your scene

• Before you start to render the passes, make sure you complete the texturing and everything in the scene is final.
• Place the lights in scene. Turn on/off the shadows as needed.
• Setup camera and create a nice composition. And save the file as Main.max.

 

Render Passes

Ambient pass

• Change the renderer to mental ray.
• In an empty material slot make mental ray material and  under basic shader select ambient/reflective occlusion (base)
• Set the sample value and max distance as needed.

Apply it to entire scene and render it. Save file as AO with file extension .tga.

 

Matte , Z-depth and Diffuse

• Open Main.max file.
• Open Render dialog and go to render elements.
• Click the Add button and select Matte,Diffuse and Z-depth.
• Hit render

 

Specular Reflection Lighting

• Open Main.max.
• Open Render dialog and go to render elements.
• Click the Add button and select Specular , Reflection and Lighting
• Hit render.
• Follow same steps for Shadows and Refraction.

 

Compositing

Diffuse Pass – Set blending mode to Normal.

Lighting – Set blending mode to Screen or Multiply depending on the scene.

Shadows – Set blending mode to multiply.

Ambient Occlusion – Set blending mode to Multiply or Overlay depending on the scene.

Reflection – Set blending mode to Add.

Specular- Set blending mode to Screen.

• Put z-depth in adjustment layer.
• Adjust the opacity of layers till you get the desired result.

Thanks for reading. Comment below if you have any questions regarding this tutorial.