[Code] How do you compute weighted vertex normals?

thomthom

I wonder if the linked article uses the face area because they computer the normals for lighting...

TIG

Several coplanar faces at a vertex are the same as one face of the same area as the bits? So the both area-weight-adjusted vertex-normals will be the same.
I think it is more for lighting...

thomthom

@tig said:

Several coplanar faces at a vertex are the same as one face of the same area as the bits? So the both area-weight-adjusted vertex-normals will be the same.

But if a vertex is connected to three sides, one large and two small, then using the area would make the normal lean toward the large area, would it not?

TIG

Not if the two small areas were equivalent to the large one... then it'd be 'balanced'...
The large area pulls it over then the 1st small are pulls it back and then the 2nd small area pulls it back again.
IF there's a large and a small area the large one 'wins'.

voljanko

By computer you mean compute?

TIG

@voljanko said:

By computer you mean compute?
A simple typo by tt in the original title - but we understood what he meant...

voljanko

I'm trying to follow your conversation,but not sure to understand what are you trying to do.
Do you want to align faces that are nearly aligned?

thomthom

@tig said:

Not if the two small areas were equivalent to the large one... then it'd be 'balanced'...
The large area pulls it over then the 1st small are pulls it back and then the 2nd small area pulls it back again.
IF there's a large and a small area the large one 'wins'.

Yes, but when they are not, which would be in any non-regular mesh. So I still wonder why one would use area to weigh the normals.

thomthom

@tig said:

@voljanko said:

By computer you mean compute?
A simple typo by tt in the original title - but we understood what he meant...

Fixed!

thomthom

@voljanko said:

I'm trying to follow your conversation,but not sure to understand what are you trying to do.
Do you want to align faces that are nearly aligned?

No, I just want to compute the vertex normals.
In this particular case I need it to be able to calculate some of the topographical characteristic of the mesh.

thomthom

My full_angle_between code seem to not work in all scenarios... back to the drawing table...

thomthom

Now I seemed to have corrected it. I had to ensure the vectors I used came in the same direction as the edge loop.