Cross Product not returning perpendicular axis

[BeachBoy]

Hey all,

I was working on a tool to instance branches along a curve when I ran into a slight issue with cross products. I'm trying to find the perpendicular axis between the tangent along a curve and a side vector so I could pitch a branch up or downwards but the vector returned by the cross function seems to pointing a weird way.

If anyone would be so kind as to take a look at this, I'd greatly appreciate it!

 

Thank you.

CrossProd_weirdness.hiplc

[ikoon]

Hi Irvin,
in the attached picture ... by typing only @tan you cast the vector into the float. You read only @tan[0].  And then you store that float into the vector tan.

If you want to read custom vector attribute, you have to type v@tan

 

 

[haggi]

Quote

vector normal = @N;
vector tan = @tan;

Instead of using @tan, you should use v@tan. Houdini only recognizes default attributes correctly. So if you use @tan, it is interpreted as one single float for all three axis. Ah.... juse a few minutes too late

Edited October 20, 2020 by haggi

[BeachBoy]

Hey Ikoon & Haggi,

Thanks, this does the trick. This is very helpful to keep in mind for the future!!