A HoverLight is a Fluent Design System paradigm that mimics a point light hovering near the surface of an object. Often used for far away interactions, the application can control the properties of a Hover Light via the HoverLight component.
For a material to be influenced by a HoverLight the Mixed Reality Toolkit/Standard shader must be used and the Hover Light property must be enabled.
Note
Up to two HoverLights are supported by default.
Most scenes within the MRTK utilize a HoverLight. The most common use case can be found on the MRTK/SDK/Features/UX/Prefabs/Cursors/DefaultCursor.prefab
By default only two HoverLights can illuminate a material at a time. If your project requires more than two HoverLights to influence a material the sample code below demonstrates how to achieve this.
Note
Having many HoverLights illuminate a material will increase pixel shader instructions and will impact performance. Please profile these changes within your project.
How to increase the number of available HoverLights
from two to four.
// 1) Within MRTK/Core/StandardAssets/Shaders/MixedRealityStandard.shader change:
#define HOVER_LIGHT_COUNT 2
// to:
#define HOVER_LIGHT_COUNT 4
// 2) Within MRTK/Core/Utilities/StandardShader/HoverLight.cs change:
private const int hoverLightCount = 2;
// to:
private const int hoverLightCount = 4;Note
If Unity logs a warning similar to below then you must restart Unity before your changes will take effect.
Property (_HoverLightData) exceeds previous array size (8 vs 4). Cap to previous >size.