I have a simple line that I extracted from some other geometry, but it seems to have no normal… (see attached file)

How do I make it have a normal?

You need to use a point SOP with “Add Normal.”

That will allow you to input custom normals.

None of your extrudes are working for me in your file, not sure why.

Check out the tangent SOP on the exchange as well. That will help you with orienting your curve normals.

thanks mightcouldb1

I did try the point SOP, but that only adds point normals, not primitive normals. See attached.

Primitive normals seem to be out of my control - in theory (as far as I know), every primitive must have a normal automatically generated by Houdini. Except that this line seems to have no normal… ?

I have been looking at this issue a little more…

It seems that lines (e.g. created using teh curve SOP) with just two points differ depending on the OS - Ubuntu versus Windows

If I use the curve SOP and click two points, then:
* On Windows, I get a line with a visible primitive normal
* On Ubuntu, I get a line with the primitive normal set to 0,0,0

I am using Windows Vista 32 bit, and Ubuntu 10.04 64 bit version.

mightcouldb1 wrote:

None of your extrudes are working for me in your file, not sure why.

I think this is why - are you using linux?