RayTracing, how to display my ray?

Hello,

I would like to display a ray I created, I'm using

ProMdl model;

ProRay ray;

ProError err;

int n_hits;

ProSelection *p_sel;

ProMdlCurrentGet(&model);

ray.start_point[0] = 0.0;

ray.start_point[1] = 0.0;

ray.start_point[2] = 0.0;

ray.dir_vector[0] = 1.0;

ray.dir_vector[1] = 1.0;

ray.dir_vector[2] = 1.0;

ProGraphicsPenPosition( ray.start_point );

ProGraphicsLineDraw( ray.dir_vector );

ProWindowRefresh( -1 );

err = ProSolidRayIntersectionCompute(model, 10.0, &ray, &p_sel, &n_hits);

I though this would be enough but apparently not...

Could you help please?

Thank you!

Emilie