How to use Corona Light Override Material - 3ds Max

The Corona Light Override Material allows you to assign different materials to the same object based on which lights affect it.

This is useful when an object should keep its regular material in the scene but render with a different material response under selected lights. It can be used for hidden text, light-revealed graphics, or UV/blacklight-style effects.

Where to find it

In 3ds Max, the material is available from:

Material/Map Browser > Materials > Corona > CoronaLightOverrideMtl

How it works

The Corona Light Override Material uses one main material and up to ten light override groups.

The object uses the material connected to the Base mtl slot as its default appearance. Each override group can then use a different material when the object is affected by the lights assigned to that group.

This allows you to create light-dependent material effects without duplicating geometry or creating separate scene versions.

Creating the Corona Light Override Material

1. Open the Slate Material Editor.
2. Right-click in the node area.
3. Go to Materials > Corona > CoronaLightOverrideMtl
   
4. Connect your base material to Base mtl slot.
5. Connect override materials to the required group Mtl slots.
6. Add the lights that should trigger each override in the group's Include list.
7. Assign the final Corona Light Override Material to the object.

Parameters

Base mtl

Defines the main material of the object. This is the default material used when no light override group applies. In most cases, this should be the regular material of the object.
 

Group 1 - 10

Each group defines one override material and the lights that should use it. Use separate groups when different lights need to produce different material responses.
 

Mtl

Defines the material used by that override group. When a light from the group's Include list affects the object, Corona uses this material for that light contribution.

Include

Defines which lights trigger the override group. Only the lights added to this list will use the material assigned to the group's Mtl slot.

Include environment

Includes environment lighting in the override group. Enable this only when the environment should also use the override material.

Example 1: 

In this example, the Corona Light Override Material is used on a teapot. The teapot keeps its regular blue material as the base material, while a second warm pink material is revealed only when the selected override light affects the object.

This means the same teapot can show two different material depending on the direction of light.

Material setup

The setup uses the following materials and nodes:

Example 2:

In this example, the Corona Light Override Material is used to reveal text on the teapot only when a specific light affects it. The teapot uses a dark red material as its normal appearance, while the override material adds bright text using a bitmap mask.

When the included light illuminates the teapot, the text becomes visible on the surface.

Material setup

The setup uses the following materials and nodes:

Notes

• The Base mtl should usually be the main material of the object.
• If no light is added in the Include field, that group will not affect the render.
• Keep group usage clean and organized to avoid confusion.
• Rename lights clearly so it is easy to understand which light controls which override.
• Use Include environment only when environment lighting should also affect the override.
• For simple scenes, one base material and one override group are usually enough.
• For complex scenes, organize groups by light purpose, such as key light, reveal light, rim light, or environment light.