TSL: Move TriplanarTexturesNode to triplanarTextures() Fn (#31285)

Author: sunag

src/nodes/Nodes.js

@@ -53,7 +53,6 @@ export { default as SetNode } from './utils/SetNode.js';
 export { default as SplitNode } from './utils/SplitNode.js';
 export { default as SpriteSheetUVNode } from './utils/SpriteSheetUVNode.js';
 export { default as StorageArrayElementNode } from './utils/StorageArrayElementNode.js';
-export { default as TriplanarTexturesNode } from './utils/TriplanarTexturesNode.js';
 export { default as ReflectorNode } from './utils/ReflectorNode.js';
 export { default as RTTNode } from './utils/RTTNode.js';
 export { default as MemberNode } from './utils/MemberNode.js';

src/nodes/TSL.js

@@ -38,7 +38,7 @@ export * from './utils/ViewportUtils.js';
 export * from './utils/RotateNode.js';
 export * from './utils/SpriteSheetUVNode.js';
 export * from './utils/Timer.js';
-export * from './utils/TriplanarTexturesNode.js';
+export * from './utils/TriplanarTextures.js';
 export * from './utils/ReflectorNode.js';
 export * from './utils/RTTNode.js';
 export * from './utils/PostProcessingUtils.js';

src/nodes/utils/TriplanarTextures.js

@@ -0,0 +1,65 @@
+import { add } from '../math/OperatorNode.js';
+import { normalLocal } from '../accessors/Normal.js';
+import { positionLocal } from '../accessors/Position.js';
+import { texture } from '../accessors/TextureNode.js';
+import { float, vec3, Fn } from '../tsl/TSLBase.js';
+
+/**
+ * TSL function for creating a triplanar textures node.
+ *
+ * Can be used for triplanar texture mapping.
+ *
+ * ```js
+ * material.colorNode = triplanarTexture( texture( diffuseMap ) );
+ * ```
+ *
+ * @tsl
+ * @function
+ * @param {Node} textureXNode - First texture node.
+ * @param {?Node} [textureYNode=null] - Second texture node. When not set, the shader will sample from `textureXNode` instead.
+ * @param {?Node} [textureZNode=null] - Third texture node. When not set, the shader will sample from `textureXNode` instead.
+ * @param {?Node<float>} [scaleNode=float(1)] - The scale node.
+ * @param {?Node<vec3>} [positionNode=positionLocal] - Vertex positions in local space.
+ * @param {?Node<vec3>} [normalNode=normalLocal] - Normals in local space.
+ * @returns {Node<vec4>}
+ */
+export const triplanarTextures = /*@__PURE__*/ Fn( ( [ textureXNode, textureYNode = null, textureZNode = null, scaleNode = float( 1 ), positionNode = positionLocal, normalNode = normalLocal ] ) => {
+
+	// Reference: https://github.com/keijiro/StandardTriplanar
+
+	// Blending factor of triplanar mapping
+	let bf = normalNode.abs().normalize();
+	bf = bf.div( bf.dot( vec3( 1.0 ) ) );
+
+	// Triplanar mapping
+	const tx = positionNode.yz.mul( scaleNode );
+	const ty = positionNode.zx.mul( scaleNode );
+	const tz = positionNode.xy.mul( scaleNode );
+
+	// Base color
+	const textureX = textureXNode.value;
+	const textureY = textureYNode !== null ? textureYNode.value : textureX;
+	const textureZ = textureZNode !== null ? textureZNode.value : textureX;
+
+	const cx = texture( textureX, tx ).mul( bf.x );
+	const cy = texture( textureY, ty ).mul( bf.y );
+	const cz = texture( textureZ, tz ).mul( bf.z );
+
+	return add( cx, cy, cz );
+
+} );
+
+/**
+ * TSL function for creating a triplanar textures node.
+ *
+ * @tsl
+ * @function
+ * @param {Node} textureXNode - First texture node.
+ * @param {?Node} [textureYNode=null] - Second texture node. When not set, the shader will sample from `textureXNode` instead.
+ * @param {?Node} [textureZNode=null] - Third texture node. When not set, the shader will sample from `textureXNode` instead.
+ * @param {?Node<float>} [scaleNode=float(1)] - The scale node.
+ * @param {?Node<vec3>} [positionNode=positionLocal] - Vertex positions in local space.
+ * @param {?Node<vec3>} [normalNode=normalLocal] - Normals in local space.
+ * @returns {Node<vec4>}
+ */
+export const triplanarTexture = ( ...params ) => triplanarTextures( ...params );