I've always thought of them as the same thing as angles, but with regards to the sphere in 3d, instead of the circle in 2D. Instead of a wedge/slice of a circle, they're a conical slice of a sphere.
[edit]and just as a 2d wedge of a circle can go past 180º and look like pac-man, these 3d cones can do the same, where they'd actually look like a sphere with a cone missing from it.[/edit]

I believe the solid angle that's common in CG is the same as this one, yes, but there's also the "differential solid angle", which is a different thing.

Isn't an azimuth/elevation pair just another way of representing a direction, which is the same thing as a surface normal?
Given two directions, you could define a cone, which could describe some slice of a sphere, which is a solid angle....?

I've always thought of them as the same thing as angles, but with regards to the sphere in 3d, instead of the circle in 2D. Instead of a wedge/slice of a circle, they're a conical slice of a sphere.

I believe the solid angle that's common in CG is the same as this one, yes, but there's also the "differential solid angle", which is a different thing.

Isn't an azimuth/elevation pair just another way of representing a direction, which is the same thing as a surface normal?
Given two directions, you could define a cone, which could describe some slice of a sphere, which is a solid angle....?

I've always thought of them as the same thing as angles, but with regards to the sphere in 3d, instead of the circle in 2D. Instead of a wedge/slice of a circle, they're a conical slice of a sphere.

I believe the solid angle that's common in CG is the same as this one, yes, but there's also the "differential solid angle", which is a different thing.