I have questions about finding outward normal vectors. Below I laid out an example and I am trying to walk through it. Basically the last four lines are questions, but I'm assuming I am correct and continuing to finish. If I am wrong, please point out where I went wrong. And if I'm right, please confirm and/or tweak, add extra insight, etc.
I have a polyhedron with 4 vertices and 4 triangular faces. The vertices are (0,0,0), (1,0,0), (0,1,0), and (0,0,1). So it has a base triangle and looks like a cone type thing with 3 triangles pointing into the z axis.
I need to find the outward normal for a face. Lets take the face that is the easiest to see - vertices (0,0,0), (1,0,0), (0,1,0) with edges [1,0,0], [-1, 1, 0], [0, -1, 0].
To get the normal I can cross product ANY two vectors? Or does it need to be a certain two?
I cross product [1,0,0] and [-1,1,0] giving me [0,0,1]. So the normal (no specification on inward or outward) is [0,0,1]...correct?
When I visualize this, the vector goes into the interior of the polyhedron rather than pointing of it. So [0,0,1] is the INWARD vector?
And to get the OUTWARD vector I just multiply it by -1 to get [0,0,-1] as the outward normal vector.
Is this correct? Any help is very appreciated.
EDIT: Was using [0,1,0] as an edge instead of [-1,1,0]