rms/resources/shaders/algorithms/raymarching.frag
2020-07-09 13:02:31 +02:00

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1 KiB
GLSL

// Requirements:
// #define MAX_STEPS 100
// #define MAX_DIST 100.
// GetDist: (vec3 position) => float
// GetDist should return the closest object point distance from position (in the whole scene)
/**
* Ray Marching algorithm
* Please take a look at: https://www.youtube.com/watch?v=PGtv-dBi2wE&t=1367s
* This function return the distance reached by the ray:
* - If dist<MAX_DIST we hit something
*/
float RayMarch(vec3 ray_origin, vec3 ray_direction) {
float dist_origin=0.; // Ray start at the origin
for(int i=0; i<MAX_STEPS; i++) { // If we take to much time to converge (i>=MAX_STEPS)
// We move the ray:
vec3 ray_position = ray_origin + ray_direction*dist_origin;
// We find the next closest point:
float closest_point = GetDist(ray_position);
// Increase the ray distance
dist_origin += closest_point;
// Check if we went to far or we are too close from a point (we hit a surface)
if(dist_origin>MAX_DIST || closest_point<SURF_DIST) break;
}
return dist_origin;
}