Failed hack for collision detection with a sphere.

[hair] / src / hair.cc

diff --git a/src/hair.cc b/src/hair.cc
index 0fc026d..b99d133 100644 (file)
--- a/src/hair.cc
+++ b/src/hair.cc
@@ -127,26 +127,6 @@ bool Hair::init(const Mesh *m, int max_num_spawns, float thresh)
 
        for(size_t i=0; i<hair.size(); i++) {
                hair[i].pos = hair[i].spawn_pt + hair[i].spawn_dir * hair_length;
-
-               /* orthonormal basis */
-               Vec3 vk = hair[i].spawn_dir;
-               Vec3 vi = Vec3(1, 0, 0);
-               if(fabs(vk.x > 0.99)) {
-                       vi = Vec3(0, -1, 0);
-               }
-               Vec3 vj = normalize(cross(vk, vi));
-               vi = cross(vj, vk);
-
-               /* identity when the hair points to the z axis */
-               Mat4 basis = Mat4(vi, vj, vk);
-
-               for(int j=0; j<3; j++) {
-                       float angle = (float)j / 3.0 * 2 * M_PI;
-                       /* dir of each anchor relative to hair root */
-                       Vec3 dir = Vec3(cos(angle), sin(angle), 0);
-                       dir = basis * dir;
-                       hair[i].anchor_dirs[j] = hair[i].pos + dir - hair[i].spawn_pt;
-               }
        }
        return true;
 }
@@ -171,8 +151,8 @@ void Hair::draw() const
 /*
                glColor3f(1, 1, 0);
                glVertex3f(hair[i].pos.x, hair[i].pos.y, hair[i].pos.z);
-               Vec3 end = hair[i].pos + dbg_force * 2.0;
-               glVertex3f(end.x, end.y, end.z);
+               Vec3 fend = hair[i].pos + dbg_force * 2.0;
+               glVertex3f(fend.x, fend.y, fend.z);
                */
        }
        glEnd();
@@ -205,8 +185,30 @@ void Hair::update(float dt)
 
                Vec3 accel = force; /* mass 1 */
                hair[i].velocity += ((-hair[i].velocity * DAMPING) + accel) * dt;
-               hair[i].pos += hair[i].velocity * dt;
+               Vec3 new_pos = hair[i].pos + hair[i].velocity * dt;
+
+               hair[i].pos = handle_collision(new_pos);
 
                dbg_force = force;
        }
 }
+
+void Hair::add_collider(CollSphere *cobj) {
+       colliders.push_back(cobj);
+}
+
+Vec3 Hair::handle_collision(const Vec3 &v) const
+{
+       /* if we transform the center and the radius of the collider sphere
+        * we might end up with a spheroid, so better just multiply the 
+        * position with the inverse transform before check for collisions :*/
+
+       Vec3 new_v = inverse(xform) * v;
+
+       for(size_t i=0; i<colliders.size(); i++) {
+               if(colliders[i]->contains(new_v)) {
+                       new_v = colliders[i]->project_surf(new_v);
+               }
+       }
+       return xform * new_v;
+}