PtFaces sith Iso option

Hi Rajaa, All,

As a follow on to the question raised yesterday.
I am turning to you with a question on the component ‘ptFaces’ with option Shape set to ‘Iso’.
Looking at the position of the Face points on the surface parametric space it does not appear to follow both U and Vs.
In this case, as per image, it runs along Vs but values of U are not at constant U

So what is the logic of the split ?
Lastly, can you pls expand on ‘Short’: Runs along Geodesics ?
The really nice thing about this command is that it allows to divide surfaces in a different way from an ‘isotrim’.
The ‘Iso’ option appears to also maintain continuity along patches in creating multispan (non uniform knot distribution) surfaces, Correct ? Is this also the case for the other ‘pull’ and ‘Short’ options.


Hi Jean
the ptFaces component should try to follow the isocurve when possible. That depends on the location of the points of each cell and if they coincide with an isocurve on the surface. If not, then the line between the 2 points is pulled to the surface.

Now I ran an example and found that there is indeed a gap between the ptFaces (with iso) and the actual isocurves. I also saw that ptIsoE created the correct edges along the isocurves. I’ll have to dig deeper to see what is going on. It might be a bug.

The ShortPath option is to find the shortest curve on surface between the 2 points. In all options, the surface continuity among neighboring faces should be the same as that of the underlying surface (unless use the “straight” option ).

Thanks for your response, Rajaa.
However, I did not expect these trims to actually be along the ISO given that these surface corner points reflect the position of their corresponding Grid Points as can be seen below.

4 of these Grid points do not appear to form two pairs of distinct 'U’s (one pair is 0 and the others are not equal to one another).
Isn’t that by design ? So as to be able to smooth out unequal velocity of the surface in the U direction when moving along V - so to speak. (67.5 KB)

Yes, this is by design, but if the points coincide along the NURBS surface U or V direction, the command should generate an edge along the iso when that option is chosen.