Determine UV island connectivity?

On 23/08/2018 at 01:42, xxxxxxxx wrote:

User Information:
Cinema 4D Version:   17 
Platform:   Windows  ;   
Language(s) :     C++  ;

For one of my plugins, I need to know the connectivity of the UVs of a polygon object.

I know how to get UV coordinates from the UVW tag. As far as I can tell, however, this is just given in a "polygon soup" format, with no connectivity information. (Which makes sense, since the UV topology/connectivity may differ from the mesh topology, i.e., there may be UV seams.)

When two polygons share a vertex, I would like to determine if they also share the same UV vertex. My idea for determining this is to look at the UV coordinates of the two "polyvertices" and determine if their UV coordinates are the same (within some tolerance). Before I implement this, I just wanted to check if there are any built in functions for this, perhaps something similar to the neighbor class, but for UVs?


On 24/08/2018 at 02:23, xxxxxxxx wrote:

Hi Filip.

I confirm there is actually no way in the SDK to know such UVW connectivity.
With that said, your approach to check UVW vertex position is correct.
I previously asked kind of similar topic Here where I end up to use Neighbor you can find my code (in python) here.

Hope it's helpful, if you have any question please let me know!

On 24/08/2018 at 02:53, xxxxxxxx wrote:

OK, good to know. Thanks Maxime!