TSL: cameraViewRotationMatrix mat3

src/nodes/accessors/Camera.js

@@ -1,7 +1,7 @@
 import { uniform } from '../core/UniformNode.js';
 import { renderGroup, sharedUniformGroup } from '../core/UniformGroupNode.js';
 import { Vector3 } from '../../math/Vector3.js';
-import { Fn, vec4 } from '../tsl/TSLBase.js';
+import { Fn, vec4, mat3 } from '../tsl/TSLBase.js';
 import { uniformArray } from './UniformArrayNode.js';
 import { builtin } from './BuiltinNode.js';
 import { screenSize } from '../display/ScreenNode.js';
@@ -197,6 +197,17 @@ export const cameraViewMatrix = /*@__PURE__*/ ( Fn( ( { camera } ) => {
 
 } ).once() )();
 
+/**
+ * TSL object that represents the world-to-view rotation matrix of the camera used for the current render.
+ *
+ * It is the upper-left 3x3 of {@link cameraViewMatrix} (translation removed) and is typically used to transform
+ * direction vectors (e.g. normals) from world space into view space.
+ *
+ * @tsl
+ * @type {Node<mat3>}
+ */
+export const worldToViewRotation = /*@__PURE__*/ mat3( cameraViewMatrix[ 0 ].xyz, cameraViewMatrix[ 1 ].xyz, cameraViewMatrix[ 2 ].xyz ).toVar();
+
 /**
  * TSL object that represents the world matrix of the camera used for the current render.
  *

src/nodes/accessors/Lights.js

@@ -1,7 +1,7 @@
 import { uniform } from '../core/UniformNode.js';
 import { renderGroup } from '../core/UniformGroupNode.js';
 import { Vector3 } from '../../math/Vector3.js';
-import { cameraViewMatrix } from './Camera.js';
+import { worldToViewRotation } from './Camera.js';
 import { positionWorld } from './Position.js';
 
 let uniformsLib;
@@ -136,4 +136,4 @@ export function lightViewPosition( light ) {
  * @param {Light} light -The light source.
  * @returns {Node<vec3>} The light's target direction.
  */
-export const lightTargetDirection = ( light ) => cameraViewMatrix.transformDirection( lightPosition( light ).sub( lightTargetPosition( light ) ) );
+export const lightTargetDirection = ( light ) => worldToViewRotation.mul( lightPosition( light ).sub( lightTargetPosition( light ) ) ).normalize();

src/nodes/accessors/Normal.js

@@ -1,5 +1,5 @@
 import { attribute } from '../core/AttributeNode.js';
-import { cameraViewMatrix } from './Camera.js';
+import { cameraViewMatrix, worldToViewRotation } from './Camera.js';
 import { modelNormalMatrix, modelWorldMatrix } from './ModelNode.js';
 import { mat3, vec3, Fn } from '../tsl/TSLBase.js';
 import { positionView } from './Position.js';
@@ -194,7 +194,7 @@ export const transformNormalToView = /*@__PURE__*/ Fn( ( [ normal ], builder ) =
 
 	const transformedNormal = modelNormalMatrix.mul( normal );
 
-	return cameraViewMatrix.transformDirection( transformedNormal );
+	return worldToViewRotation.mul( transformedNormal ).normalize();
 
 } );