Replaced the collision detection with a check of the angle

Instead of performing collision detection with a sphere, I now calculate
the dot product between the normal and the hair and if it's negative (=>
the hair falls inside the head) we calc the projection of the hair on
the head and find the new position from that.

diff --git a/src/hair.cc b/src/hair.cc
index ef93f2c..b2eb4a0 100644 (file)
--- a/src/hair.cc
+++ b/src/hair.cc
@@ -187,7 +187,20 @@ void Hair::update(float dt)
                hair[i].velocity += ((-hair[i].velocity * DAMPING) + accel) * dt;
                Vec3 new_pos = hair[i].pos + hair[i].velocity * dt;
 
-               hair[i].pos = new_pos; //= handle_collision(new_pos);
+               /* collision detection with the head */
+               Vec3 normal = xform.upper3x3() * hair[i].spawn_dir;
+               Vec3 root = xform * hair[i].spawn_pt;
+               Vec3 dir = new_pos - root;
+               
+               normal.normalize();
+
+               /* angle that will cause the hair to be rendered inside the head */
+               float d = dot(dir, normal);
+               if(d < 0) {
+                       new_pos += -d * normal;
+               }
+
+               hair[i].pos = handle_collision(new_pos);
 
                dbg_force = force;
        }

diff --git a/src/main.cc b/src/main.cc
index 852b7cb..0fceafe 100644 (file)
--- a/src/main.cc
+++ b/src/main.cc
@@ -33,7 +33,7 @@ static int win_width, win_height;
 static float cam_theta, cam_phi = 25, cam_dist = 8;
 static float head_rz, head_rx; /* rot angles x, z axis */
 static Mat4 head_xform;
-static CollSphere coll_sphere; /* sphere used for collision detection */
+//static CollSphere coll_sphere; /* sphere used for collision detection */
 
 int main(int argc, char **argv)
 {
@@ -105,15 +105,15 @@ static bool init()
                return false;
        }
 
-       coll_sphere.radius = 1.0;
-       coll_sphere.center = Vec3(0, 0.6, 0.53);
+//     coll_sphere.radius = 1.0;
+//     coll_sphere.center = Vec3(0, 0.6, 0.53);
 
        if(!hair.init(mesh_head, MAX_NUM_SPAWNS, THRESH)) {
                fprintf(stderr, "Failed to initialize hair\n");
                return false;
        }
 
-       hair.add_collider(&coll_sphere);
+//     hair.add_collider(&coll_sphere);
 
        return true;
 }