Get vertex normals from a triangle, hit by a raycast?

RumbleMonk · February 15, 2022, 6:11pm

Does anyone know how to, in blueprints ideally, get vertex normals from a face ID?

I’m shooting out a ray onto polygons, and want to get the vertex normals of polygon hit so that I can calculate barycentric coordinates from those.

I can’t seem to figure out how to get anything useful from Face ID from the result of the raycast, but was hoping there would be a simple FaceID → GetVertexArray → GetVertNormal type methods to play with here.

I would be surprised if this wasn’t exposed to blueprints… but maybe that is the case?

Thanks for any help!

ClockworkOcean · February 15, 2022, 6:13pm

I thought the normal pin from the standard line trace, was the vertex normal?

RumbleMonk · February 16, 2022, 4:24am

Thanks for the replay.

That would be the face normal of the polygon that was hit I’m pretty sure. I’d want the normals from 3 vertices that make up that polygon/face.

ClockworkOcean · February 16, 2022, 8:12am

Correct, that’s what I thought you meant

For the verts, no idea, I’m afraid…

RumbleMonk · February 17, 2022, 12:56am

Ok, thanks for trying though… let’s see if anyone else have any ideas cause I’m all out of them.

Thee_MuffinMan · February 17, 2022, 1:37am

I know how to get ALL the vertices for a given static mesh.

Unfortunately I don’t know how you would get the exact verts for any given face. Sorry

Maybe this could help though?

In the static mesh enable “Allow CPU Access”
In BP use “get section from static mesh”

pezzott1 · February 17, 2022, 2:13am

By distance from hit location, maybe?

That means looping though until found.