Depth, Dust, & Position Procedural Masks

This tutorial shows how to create Z Depth, dust, and Object Position masks that can be used in a compositing package to layer shading effects such as depth of field, dirt, dust, or snow. They use a combination of Arnold shaders such as utility, range, and state_float. Thanks to Slava Sych for the assistance with this tutorial.

 

Depth Mask

• Create a state_float shader. Set the variable parameter to ray_length (Rl).

• Create a range shader and connect the state_float shader output to the input of the range shader. Change the following parameters of the range shader:

• • input_min: 0.6 (this value depends on the distance from the camera your object is).

• • output_max: 1.5 (this value depends on the distance from the camera your object is).

• • smoothstep: Enabled

 

Object Position (n) Dust Mask

• Create a utility shader. Set the following parameters for the utility shader:

• • color_mode: normal (n)

• • shade_mode: flat

• Create a range shader and connect the utility shaders Output.G to the input of the range shader. Enable smoothstep and control the mask position with the input_min/max parameters.

 

Object Position (P) Mask

• Create a utility shader. Set the following parameters for the utility shader:

• • color_mode: shading point (P)

• • shade_mode: Flat

• Create a range shader and connect the utility shaders Output.G to the Input of the Range shader. Enable smoothstep and control the mask position with the input_min/max parameters.