GPU Pro 6

2. Implementing a GPU-Only Particle-Collision System with ASTC 3D Textures and OpenGL ES 3.0 379

float slidingFactor = clamp ( uParticleMass , 0.0 ,1.0 ) ;

vec3 velocityDir = normalize( iparticle_Vel );

vec3 tangentDir = cross( surfaceNormal . xyz , velocityDir );

if( length ( tangentDir) < 0.0001 )

{

tangentDir = getRandomTangentDir ( surfaceNormal . xyz ,0.0);

}

iparticle_Vel = length ( iparticle_Vel )

( surfaceNormal . xyz slidingFactor +

tangentDir . xyz (1.0− slidingFactor ))

uBouncingResistance ;

Listing 2.3. Particle-collision behavior.

interesting, some randomness can be added while the particles are flowing and

no collision occurred. The fragmen