+/*
+ * Cast a sphere from a to b and see what time it hits
+ */
+VG_STATIC int spherecast_world( v3f pa, v3f pb, float r, float *t, v3f n )
+{
+ bh_iter it;
+ bh_iter_init( 0, &it );
+
+ boxf region;
+ box_init_inf( region );
+ box_addpt( region, pa );
+ box_addpt( region, pb );
+
+ v3_add( (v3f){ r, r, r}, region[1], region[1] );
+ v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
+
+ v3f dir;
+ v3_sub( pb, pa, dir );
+
+ v3f dir_inv;
+ dir_inv[0] = 1.0f/dir[0];
+ dir_inv[1] = 1.0f/dir[1];
+ dir_inv[2] = 1.0f/dir[2];
+
+ int hit = -1;
+ float min_t = 1.0f;
+
+ int idx;
+ while( bh_next( world.geo_bh, &it, region, &idx ) )
+ {
+ u32 *ptri = &world.scene_geo->arrindices[ idx*3 ];
+ v3f tri[3];
+
+ boxf box;
+ box_init_inf( box );
+
+ for( int j=0; j<3; j++ )
+ {
+ v3_copy( world.scene_geo->arrvertices[ptri[j]].co, tri[j] );
+ box_addpt( box, tri[j] );
+ }
+
+ v3_add( (v3f){ r, r, r}, box[1], box[1] );
+ v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
+
+ if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
+ continue;
+
+ float t;
+ v3f n1;
+ if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) )
+ {
+ if( t < min_t )
+ {
+ min_t = t;
+ hit = idx;
+ v3_copy( n1, n );
+ }
+ }
+ }
+
+ *t = min_t;
+ return hit;
+}
+