Averaging normals

OpenGL OpenGL: Basic Coding
1

How?

2

You have to learn the linear algebra to calculate the normals.

3

Pseudocode:

NORMAL result = 0;

for(i = 0; i < number of normals; i++)
result += normal[i];

normal /= number of normals;

j

4

The above code needs to have the line:
“normal /= number of normals” replaced with normal.normalize().

This is because, for instance, if one normal is 0,0,1 and another is 0,1,0 you would get 0,0.5,0.5 as the answer which is not unit length.

– Zeno

5

Is it…

NORMAL result = 0;

for(i = 0; i < total_of_normals; i++)
{
result += normal[i];
}

normal /= total_of_normals;
normalize(result);

6

You don’t have to divide by the number of normals at all. Just sum them and normalize the resulting vector.

7