BatchedMesh: Remove unneeded & redundant matrices array (#27130)

* Add support for multi draw

* Fix multidraw

* Add batching material properties

* Adjust batching define

* Move normal shaders

* Move vertex transform shadres

* Move batching pars

* Move batching matrix fetch

* Switch _batch_id_ to batchId

* Remove custom shader callback

* Remove "matrices" array

* Remove unused custom uniforms

* Remove unneeded field

examples/jsm/objects/BatchedMesh.js

@@ -20,6 +20,10 @@ const _zeroScaleMatrix = new Matrix4().set(
 
 // @TODO: SkinnedMesh support?
 // @TODO: Future work if needed. Move into the core. Can be optimized more with WEBGL_multi_draw.
+// @TODO: geometry.groups support?
+// @TODO: geometry.drawRange support?
+// @TODO: geometry.morphAttributes support?
+// @TODO: Support uniform parameter per geometry
 
 // copies data from attribute "src" into "target" starting at "targetOffset"
 function copyAttributeData( src, target, targetOffset = 0 ) {
@@ -76,9 +80,6 @@ class BatchedMesh extends Mesh {
 		this._multiDrawCount = 0;
 
 		// Local matrix per geometry by using data texture
-		// @TODO: Support uniform parameter per geometry
-
-		this._matrices = [];
 		this._matricesTexture = null;
 
 		// @TODO: Calculate the entire binding box and make frustumCulled true
@@ -110,10 +111,6 @@ class BatchedMesh extends Mesh {
 
 	_initializeGeometry( reference ) {
 
-		// @TODO: geometry.groups support?
-		// @TODO: geometry.drawRange support?
-		// @TODO: geometry.morphAttributes support?
-
 		const geometry = this.geometry;
 		const maxVertexCount = this._maxVertexCount;
 		const maxGeometryCount = this._maxGeometryCount;
@@ -328,7 +325,6 @@ class BatchedMesh extends Mesh {
 		const visible = this._visible;
 		const active = this._active;
 		const matricesTexture = this._matricesTexture;
-		const matrices = this._matrices;
 		const matricesArray = this._matricesTexture.image.data;
 
 		// push new visibility states
@@ -340,7 +336,6 @@ class BatchedMesh extends Mesh {
 		this._geometryCount ++;
 
 		// initialize matrix information
-		matrices.push( new Matrix4() );
 		_identityMatrix.toArray( matricesArray, geometryId * 16 );
 		matricesTexture.needsUpdate = true;
 
@@ -490,56 +485,48 @@ class BatchedMesh extends Mesh {
 		// @TODO: Map geometryId to index of the arrays because
 		//        optimize() can make geometryId mismatch the index
 
-		const visible = this._visible;
 		const active = this._active;
 		const matricesTexture = this._matricesTexture;
-		const matrices = this._matrices;
 		const matricesArray = this._matricesTexture.image.data;
-		if ( geometryId >= matrices.length || active[ geometryId ] === false ) {
+		const geometryCount = this._geometryCount;
+		if ( geometryId >= geometryCount || active[ geometryId ] === false ) {
 
 			return this;
 
 		}
 
-		if ( visible[ geometryId ] === true ) {
-
-			matrix.toArray( matricesArray, geometryId * 16 );
-			matricesTexture.needsUpdate = true;
-
-		}
-
-		matrices[ geometryId ].copy( matrix );
+		matrix.toArray( matricesArray, geometryId * 16 );
+		matricesTexture.needsUpdate = true;
 
 		return this;
 
 	}
 
 	getMatrixAt( geometryId, matrix ) {
 
-		const matrices = this._matrices;
 		const active = this._active;
-		if ( geometryId >= matrices.length || active[ geometryId ] === false ) {
+		const matricesArray = this._matricesTexture.image.data;
+		const geometryCount = this._geometryCount;
+		if ( geometryId >= geometryCount || active[ geometryId ] === false ) {
 
-			return matrix;
+			return null;
 
 		}
 
-		return matrix.copy( matrices[ geometryId ] );
+		return matrix.fromArray( matricesArray, geometryId * 16 );
 
 	}
 
 	setVisibleAt( geometryId, value ) {
 
 		const visible = this._visible;
 		const active = this._active;
-		const matricesTexture = this._matricesTexture;
-		const matrices = this._matrices;
-		const matricesArray = this._matricesTexture.image.data;
+		const geometryCount = this._geometryCount;
 
 		// if the geometry is out of range, not active, or visibility state
 		// does not change then return early
 		if (
-			geometryId >= visible.length ||
+			geometryId >= geometryCount ||
 			active[ geometryId ] === false ||
 			visible[ geometryId ] === value
 		) {
@@ -548,18 +535,6 @@ class BatchedMesh extends Mesh {
 
 		}
 
-		// scale the matrix to zero if it's hidden
-		if ( value === true ) {
-
-			matrices[ geometryId ].toArray( matricesArray, geometryId * 16 );
-
-		} else {
-
-			_zeroScaleMatrix.toArray( matricesArray, geometryId * 16 );
-
-		}
-
-		matricesTexture.needsUpdate = true;
 		visible[ geometryId ] = value;
 		return this;
 
@@ -569,9 +544,10 @@ class BatchedMesh extends Mesh {
 
 		const visible = this._visible;
 		const active = this._active;
+		const geometryCount = this._geometryCount;
 
 		// return early if the geometry is out of range or not active
-		if ( geometryId >= visible.length || active[ geometryId ] === false ) {
+		if ( geometryId >= geometryCount || active[ geometryId ] === false ) {
 
 			return false;