UeSpotLightShadow

UeSpotLightShadow manages shadows for UeSpotLight using a single perspective camera approach. Since spot lights emit light in a cone, a single perspective camera is sufficient to cover the illuminated area.

Overview

• Uses a single UePerspectiveCamera to render the shadow map.
• The camera's Field of View (FOV) is automatically synchronized with the UeSpotLight angle.
• Generates a depth texture used by shaders for shadow calculation.
• Computes a lightSpaceMatrix (projection * view) used for vertex transformation in the shadow pass.
• Automatically updates its matrices when the light moves or changes its target/angle.

Shader usage

The standard shader sh_ue_standard automatically handles spot shadows if enabled. It uses the u_ueSpotShadowEnabled uniform, the u_ueSpotShadowMatrix uniform, and the s_spotShadowMap sampler.

API

• UeSpotLightShadow(data = {}) - Constructor.
  • data.shadowNear - Near plane distance for the camera (default 0.5).
  • data.shadowFar - Far plane distance for the camera (default 500).
  • data.mapSize - Struct with width and height for the shadow map (default 512x512).

Key methods:

• updateMatrices(light) - Updates the internal camera and shadow matrix based on the provided light's properties.
• dispose() - Release resources.

Example

spotLight = new UeSpotLight(c_white, 1, 600, degtorad(45));
spotLight.castShadow = true;
spotLight.position.set(0, 200, 0);
spotLight.target.position.set(0, 0, 0);
scene.add(spotLight);