Hi Olga, can you please attach a .3dm model file of your shapes so I can take a look at the model over here instead of only screenshots? If you want to keep your data private you can e-mail it to me at moi@moi3d.com .

Often times a problem may involve things that are very particular to your model file, that are often not easy to see in a screenshot (for example, doubled objects, etc...).

So in general it really helps if you can attach the model file for me to examine.

- Michael

Hi Michael
It tried it in new files several times
The same problem persists
Please see one of these files.
It MOI 1 this does not happen
Thanks
Olga

Thanks Olga, I can repeat the problem over here. It will probably take me a little while to figure out why this one works better in v1, one of the fixes to the geometry library in v2 for some other case has made this case not work anymore. Unfortunately that kind of thing can tend to happen when adjusting algorithms for geometric processing.

One thing you can do for now to make this kind of thing easier for MoI to calculate is to extend that line out so that it goes beyond the surface instead of stopping right at the surface boundary.

For instance like this:



That kind of extension will avoid this problem.

- Michael

Thanks Michael
Please notice after following your advice there are no two projection lines but still that intersection point catches two different points.

Hi Olga - it is normal for operations that involve intersections with surfaces (like curve projection or surface/surface intersection) to be calculated to an accuracy level of 0.001 units.

It looks like you have probably zoomed in quite a bit there in your close up view, and if you draw a line between those 2 points you should probably see that distance is smaller than the 0.001 tolerance value.

So that is not unusual that things can get to be off by that amount, when you join pieces later on into a solid, it will allow joins to happen between pieces that are up to 0.005 units apart, so that is not necessarily going to cause any problems...

What is your final goal for this?

If you are trying to gouge out a piece, it can be easier to do it with a boolean operation rather than individual curve projections.

That would look something like this - draw a line to close the curve, and join it together to make a closed outline.

Select your cylinder, run Construct / Boolean / Difference:



To produce this result:



- Michael

Thanks Michael
I need project command for various ring shank shapes.
The project command is a must for me at the moment so I will have to go to MOI 1 or Rhino for it.
Yes, thanks I understand about tolerance.
But please notice that the photos above close-up photos – they are not close-up yet snap catches two intersections.
And as I said above MOI 1 does produce only one intersection there.

Thanks
Olga