divide integration steps & constraint iterations

Signed-off-by: Guilherme Avila <[email protected]>

Author: sciecode

src/glsl/constraints.frag.js

@@ -29,7 +29,8 @@ vec2 getUV( float id ) {
 vec3 getDisplacement( vec3 point0, vec3 point1, float restDistance ) {
 
     float curDistance = distance( point0, point1 );
-	return 1.5 * ( curDistance - restDistance ) * ( point1 - point0 ) / curDistance;
+	if (curDistance < 0.0001) return vec3(0.0);
+	return .5 * ( curDistance - restDistance ) * ( point1 - point0 ) / curDistance;
 	
 }
 
@@ -80,7 +81,7 @@ void main() {
     displacement += getDisplacement( p0, p5, distancesB.x );
     displacement += ( adjacentB.y > 0.0 ) ? getDisplacement( p0, p6, distancesB.y ) : vec3( 0 );
 
-	p0 += 0.76 * displacement / ( ( adjacentB.y > 0.0 ) ? 6.0 : 5.0 );
+	p0 += displacement / ( ( adjacentB.y > 0.0 ) ? 6.0 : 5.0 );
 
 	gl_FragColor = vec4( unpackPosition( p0 ), 1.0 );
 

src/glsl/integrate.frag.js

@@ -29,10 +29,11 @@ void main() {
 	vec3 prv = ( texture2D( tPrevious0, uv ).xyz + texture2D( tPrevious1, uv ).xyz ) / 1024.0;
 	vec3 pos = ( texture2D( tPosition0, uv ).xyz + texture2D( tPosition1, uv ).xyz ) / 1024.0;
 
-	vec3 offset = ( org - pos ) * 260.5 * dt2;
-	vec3 disp = ( pos - prv ) * 0.94 + pos;
+	vec3 accel = 345.*(org-pos);
+	vec3 vel = (pos-prv)/dt+accel*dt;
+	vec3 disp = 0.98*vel*dt;
 
-	gl_FragColor = vec4( unpackPosition( disp + offset ), 1.0 );
+	gl_FragColor = vec4( unpackPosition( pos + disp ), 1.0 );
 
 }
 `;

src/modules/fbo.js

@@ -14,8 +14,8 @@ RESOLUTION,
 renderer, mesh, targetRT, normalsRT,
 originalRT, previousRT, positionRT,
 adjacentsRT, distancesRT,
-steps = 40, prevTime, dt;
-
+iterations = 5, steps = 6,
+prevTime, dt;
 
 const
 tSize = new THREE.Vector2(),
@@ -300,19 +300,18 @@ function computeVertexNormals( ) {
 function update() {
 
 	const now = performance.now();
-	dt = Math.min(now - prevTime, 33.333)/1000;
+	const frame_dt = Math.min(now - prevTime, 33.333)/1000;
+	dt = frame_dt/steps;
 	prevTime = now;
 
-	integrate();
-
 	let mouseUpdating = MOUSE.updating();
 
 	for ( let i = 0; i < steps; i++ ) {
-
-		if ( mouseUpdating && i < steps - 5 ) mouseOffset();
-
-		solveConstraints();
-
+		integrate();
+		for ( let j = 0; j < iterations; j++ ) {
+			if ( mouseUpdating && (i<steps-2||j<iterations-2) ) mouseOffset();
+			solveConstraints();
+		}
 	}
 
 	computeVertexNormals();