 }
 
 // tracer parameters
-#define N_BOUNCES 6
-#define IMAGE_BRIGHTNESS 25.0
+#define N_BOUNCES 4
+#define IMAGE_BRIGHTNESS 1.0
 
 // secene geometry
 #define OBJ_NONE 0

  return normal * sqrt(1.0 - r) + dir * sqrt(r);
}

float weight1(float p1, float p2) {
    //return 0.5;
    //return p1 / (p1 + p2); // balance heuristic

    float choice_sample = random_choice_sample;
    int light_object = select_light(light_point, light_sample_area_probability, choice_sample);
    get_emission(light_object, light_emission);
    light_emission *= N_LIGHTS;

    // ray location on image surface after applying tent filter
    vec2 ccd_pos = get_ccd_pos(gl_FragCoord.xy);
