What's the best way to generate perpendicular normals like this?

[magneto]

Hi,

Imagine 4 lines that are positioned to appear like a quad. I am trying to generate normals that look like the image below:

Polyframe only generates tangents correctly, otherwise it's all 0,0,0. I tried using 1 line that's all connected, and then Polyframe generates half of the normals correctly, the other half is set to world Y.

So not sure how to do this procedurally. Any ideas?

Thanks

[Guest mantragora]

should_work_on_arbitrary_position.hip

[magneto]

Thanks mantragora, that's novel idea I wonder if it can be done without scaling to 0 and then fusing to get the center? I think it might be possible using the AttribWrangle to create primitive attributes and then demote it to point attribs.

[Guest mantragora]

should_work_on_arbitrary_position_2.hip

[magneto]

Thanks mantragora, I did it with the AttribWrangle using this code:

vector center = ch("center");
@N = @P - center;[/CODE]

by adding a center parameter to the node using the centroid expression. After that just demoted N to point normals. Pretty slick

Edited August 5, 2013 by magneto

[yongbin]

how about this?

N_from_connected_line.hipnc

Edited August 8, 2013 by yongbin

[magneto]

Thanks yongbin, that's also an interesting way to solve it

[hombrezoo]

Hello guys, I may be a little late to the party, but here is my contribution as I was looking for this exact same thing I found an extra step to also get the normals pointing outwards from corners to point in its average direction as well.

Hope it helps.

 

P

outwardNormals.hipnc

Edited September 27, 2019 by hombrezoo
better grammar, I guess.