https://github.com/WWBN/AVideo/issues/8713

node_modules/three/examples/js/postprocessing/MaskPass.js

@@ -0,0 +1,102 @@
+THREE.MaskPass = function ( scene, camera ) {
+
+	THREE.Pass.call( this );
+
+	this.scene = scene;
+	this.camera = camera;
+
+	this.clear = true;
+	this.needsSwap = false;
+
+	this.inverse = false;
+
+};
+
+THREE.MaskPass.prototype = Object.assign( Object.create( THREE.Pass.prototype ), {
+
+	constructor: THREE.MaskPass,
+
+	render: function ( renderer, writeBuffer, readBuffer /*, deltaTime, maskActive */ ) {
+
+		var context = renderer.getContext();
+		var state = renderer.state;
+
+		// don't update color or depth
+
+		state.buffers.color.setMask( false );
+		state.buffers.depth.setMask( false );
+
+		// lock buffers
+
+		state.buffers.color.setLocked( true );
+		state.buffers.depth.setLocked( true );
+
+		// set up stencil
+
+		var writeValue, clearValue;
+
+		if ( this.inverse ) {
+
+			writeValue = 0;
+			clearValue = 1;
+
+		} else {
+
+			writeValue = 1;
+			clearValue = 0;
+
+		}
+
+		state.buffers.stencil.setTest( true );
+		state.buffers.stencil.setOp( context.REPLACE, context.REPLACE, context.REPLACE );
+		state.buffers.stencil.setFunc( context.ALWAYS, writeValue, 0xffffffff );
+		state.buffers.stencil.setClear( clearValue );
+		state.buffers.stencil.setLocked( true );
+
+		// draw into the stencil buffer
+
+		renderer.setRenderTarget( readBuffer );
+		if ( this.clear ) renderer.clear();
+		renderer.render( this.scene, this.camera );
+
+		renderer.setRenderTarget( writeBuffer );
+		if ( this.clear ) renderer.clear();
+		renderer.render( this.scene, this.camera );
+
+		// unlock color and depth buffer for subsequent rendering
+
+		state.buffers.color.setLocked( false );
+		state.buffers.depth.setLocked( false );
+
+		// only render where stencil is set to 1
+
+		state.buffers.stencil.setLocked( false );
+		state.buffers.stencil.setFunc( context.EQUAL, 1, 0xffffffff ); // draw if == 1
+		state.buffers.stencil.setOp( context.KEEP, context.KEEP, context.KEEP );
+		state.buffers.stencil.setLocked( true );
+
+	}
+
+} );
+
+
+THREE.ClearMaskPass = function () {
+
+	THREE.Pass.call( this );
+
+	this.needsSwap = false;
+
+};
+
+THREE.ClearMaskPass.prototype = Object.create( THREE.Pass.prototype );
+
+Object.assign( THREE.ClearMaskPass.prototype, {
+
+	render: function ( renderer /*, writeBuffer, readBuffer, deltaTime, maskActive */ ) {
+
+		renderer.state.buffers.stencil.setLocked( false );
+		renderer.state.buffers.stencil.setTest( false );
+
+	}
+
+} );