DoubleSide check.

Author: gonnavis

examples/jsm/postprocessing/SSShadowPass.js

@@ -43,6 +43,7 @@ class SSRrPass extends Pass {
 		this.lightPosition = SSRrShader.uniforms.lightPosition.value;
 		this.maxDistance = SSRrShader.uniforms.maxDistance.value;
 		this.surfDist = SSRrShader.uniforms.surfDist.value;
+		this.doubleSideCheckStartFrom = SSRrShader.uniforms.doubleSideCheckStartFrom.value;
 
 		this.encoding = encoding;
 
@@ -229,6 +230,7 @@ class SSRrPass extends Pass {
 		this.ssrrMaterial.uniforms[ 'lightPosition' ].value = this.lightPosition;
 		this.ssrrMaterial.uniforms[ 'maxDistance' ].value = this.maxDistance;
 		this.ssrrMaterial.uniforms[ 'surfDist' ].value = this.surfDist;
+		this.ssrrMaterial.uniforms[ 'doubleSideCheckStartFrom' ].value = this.doubleSideCheckStartFrom;
 		this.renderPass( renderer, this.ssrrMaterial, this.ssrrRenderTarget );
 
 		// output result to screen

examples/jsm/shaders/SSShadowShader.js

@@ -27,6 +27,7 @@ const SSRrShader = {
 		'cameraRange': { value: 0 },
 		'maxDistance': { value: 180 },
 		'surfDist': { value: .007 },
+		'doubleSideCheckStartFrom': { value: .01 },
 
 	},
 
@@ -61,6 +62,7 @@ const SSRrShader = {
 		uniform mat4 cameraInverseProjectionMatrix;
 		uniform float maxDistance;
 		uniform float surfDist;
+		uniform float doubleSideCheckStartFrom;
 		#include <packing>
 		float pointToLineDistance(vec3 x0, vec3 x1, vec3 x2) {
 			//x0: point, x1: linePointA, x2: linePointB
@@ -173,7 +175,12 @@ const SSRrShader = {
 				gl_FragColor=texture2D(tDiffuse,vUv);
 				if(hit){
 					vec3 vN=getViewNormal( uv );
-					if(dot(viewRefractDir,vN)>=0.) continue;
+
+					// if(dot(viewRefractDir,vN)>=0.) continue;
+
+					if((length(viewPosition-vP)<doubleSideCheckStartFrom)&&(dot(viewRefractDir,vN)>=0.)) continue;
+					// May not need "doubleSideCheckStartFrom", use "surfDist" or change starting "i" of "for(float i=1.;i<float(MAX_STEP);i++){" instead.
+
 					gl_FragColor.rgb*=.5;
 					return;
 				}

examples/screenshots/webgl_postprocessing_ssshadow.jpg

@@ -33,7 +33,7 @@
 
 		const params = {
 			enableSSRr: true,
-			autoRotate: true,
+			autoRotate: false,
 		};
 		let composer;
 		let ssrrPass;
@@ -179,9 +179,10 @@
 
 			gui = new GUI();
 			gui.add( params, 'enableSSRr' ).name( 'Enable SSRr' );
-			gui.add( ssrrPass.lightPosition, 'x' ).min( 0 ).max( 10 ).step( .0001 );
-			gui.add( ssrrPass.lightPosition, 'y' ).min( 0 ).max( 10 ).step( .0001 );
-			gui.add( ssrrPass.lightPosition, 'z' ).min( 0 ).max( 10 ).step( .0001 );
+			gui.add( ssrrPass.lightPosition, 'x' ).name('lightX').min( 0 ).max( 10 ).step( .0001 );
+			gui.add( ssrrPass.lightPosition, 'y' ).name('lightY').min( 0 ).max( 10 ).step( .0001 );
+			gui.add( ssrrPass.lightPosition, 'z' ).name('lightZ').min( 0 ).max( 10 ).step( .0001 );
+			gui.add( ssrrPass, 'doubleSideCheckStartFrom' ).min( 0 ).max( .1 ).step( .0001 );
 			gui.add( params, 'autoRotate' ).onChange( () => {
 
 				controls.enabled = ! params.autoRotate;