Lo there.
Bit of a rookie question today.
I’m reading through the section of the manual titled “Advanced operations with Panda’s internal structures” and I’m a little confused about normals.
First of, are normals just the direction pointing away from the surface? So that on a flat plane, the vertex normal would point straight up?
How to calculate them? I see them calculated in the cube sample, but some other source code, and the manual just sets them all to (0,0,1). I assume in those cases the author IS drawing a flat plane and IS pointing the normal straight up like my earlier example.
for a face-normal this would be correct. but most of the time you would work with vertex normals (to get a more smooth-looking shading instead of the flat shaded look)
there are different ways to calculate them. the internet is full of “normal calcultaion algorithms”
its mostly about shadeing itself but at the beginning they compute the normals.
in one sentence. a vertex normal is calculated as average of the orthogonals , standing on the lines connecting it to other vertices.
well in some special cases you would even want to use totaly different calculations. for exmaple if you have grass-meshes with planes+grastexture applied. you most likely want you vertex normals to point straight upwards.
You can run your models through a panda utility (I believe egg-trans) which can generate normals automatically.
Also, you can also specify to automatically generate normals in any of the something2egg converters.
