with latest code,sometimes get error:
AssertionError: !pmin.is_nan()
void Geom::
compute_internal_bounds(Geom::CData *cdata, Thread *current_thread) const {
int num_vertices = 0;
// Get the vertex data, after animation.
CPT(GeomVertexData) vertex_data = cdata->_data.get_read_pointer(current_thread);
vertex_data = vertex_data->animate_vertices(true, current_thread);
// Now actually compute the bounding volume. We do this by using
// calc_tight_bounds to determine our box first.
LPoint3 pmin, pmax;
PN_stdfloat sq_center_dist;
bool found_any = false;
do_calc_tight_bounds(pmin, pmax, sq_center_dist, found_any,
vertex_data, false, LMatrix4::ident_mat(),
InternalName::get_vertex(),
cdata, current_thread);
nassertv(!pmin.is_nan());
nassertv(!pmax.is_nan());