I'm trying to create a galaxy simulation using opengl with the compute shader and when I start my simulation, the galaxy with the spiral arms doesn't form, instead it goes into chaos. I noticed that the particles in the center are not spinning fast enough Does anyone had this problem before ?
I tried to:
- change mass and smooth value
- using verlet integration
- change velocity initial value
- change the number of particles
here is the code:
#version 430 core
layout (local_size_x = 128, local_size_y = 1, local_size_z = 1) in;
struct Particle
{
vec4 position;
vec4 velocity;
vec4 acceleration;
};
layout (std430, binding = 0) buffer ParticleBuffer {
Particle p[];
};
uniform float dt;
uniform float accuracy;
const float mass = 1e-5;
const float csmooth = 1e-6;
vec3 compute_force(vec3 posi){
vec3 f = vec3(0);
for(int i = 0; i<accuracy*p.length(); i++){
if(posi != p[i].position.xyz){
vec3 v = p[i].position.xyz - posi;
float d = length(v);
f+= mass*v/(pow(d,3)+csmooth);
}
}
return f;
}
void main() {
uint index = gl_GlobalInvocationID.x;
vec3 pos = p[index].position.xyz;
vec3 vel = p[index].velocity.xyz;
vec3 accel = p[index].acceleration.xyz;
vec3 newPos = pos+vel*dt + accel*(dt*dt*0.5);
vec3 newAccel = compute_force(pos);
vec3 newVel = vel + (accel+newAccel) *(dt*0.5);
p[index].position.xyz = newPos;
p[index].velocity.xyz = newVel;
p[index].acceleration.xyz = newAccel;
}
```
