Well, currently we are interested in cylinders and spheres, but I believe that this list may expand in the future. For each surface type it would be nice to have all the information to fully determine the surface itself. Again, for our current goals we just need to understand if the point lies on the surface.

For example, for cylinder we expect to have center, direction (the axis), radius and height. Probably the height can be just the length of the axis of the cylinder. For sphere we expect to have center and radius.

I have tried the approach you offered, using 'getParametrization' and 'isInside' functions, but I think I miss some basic concepts or basic understanding of what these functions give me. First of all, 'getParametrization' doesn't work for cylinders and tori, I get an error saying "OCC projection of point on surface failed" Secondly, I was testing combination of these 2 function for spheres. I got the parameterization of point [0, 0, 0] and queried if it was inside, and I got true for all the spheres, however the point [0, 0, 0] wasn't on the surface of any spheres.

As for the closest point, I expected this function to return the closest point on the surface. It works in a little bit different way for planes, just a projection, but for cylinders and tori the function just returns [0, 0, 0].

Could you please explain how can we use `getParametrization`

and `isInside`

to determine if any point lies on the surface or not?

Thank you for answers, that helped to understand how we can proceed.

Is there any information available regarding upcoming developments for interface for surface-dependent information?

I have a **OCC brep** file and the tags of some surfaces in this file.
I want to extract enough information in order to be able to determine if the point lies on the surface or not. (to determine if the triangle lies on the surface)

Unfortunately, we are only able to do this for the Plane surface type, using * gmsh/model/getNormal* and

- How can we get information about center, direction, radius?

Another way to do it is by directly parsing the **OCC brep** file, but the order of the surfaces in the file doesn't correspond to the order of tags when we import same file in gmsh.

- Is there any way to determine what the surface tag will be just having a file, without importing it?