There are a billion equations, and the use of many of them is not immediately apparent. :-)
For example, I could tell you the plane equation, but that would be useless to you if you don't know enough math to find clever ways to make use of it because you don't understand what the equation represents.
Look in the code archives for Ray Intersect Triangle, a function I wrote, and take a look at the source to that and you'll leanr how to determine if a ray is intersecting a triangle, but also how to use the dot product equation to determine how much a vector points in the same direction as another vector, and how to use the cross product to take two vectors and find a third which is at 90 degrees to them. (Ie, the normal of a triangle, if given two sides of the triangle for the vectors.)
And that's just the tip of the iceberg. I have a whole text file full of various equations which are useful for making games, but right now they're probably too complicated for you to use if you just learned the distance equation. :-)
For example, I could tell you the plane equation, but that would be useless to you if you don't know enough math to find clever ways to make use of it because you don't understand what the equation represents.
Look in the code archives for Ray Intersect Triangle, a function I wrote, and take a look at the source to that and you'll leanr how to determine if a ray is intersecting a triangle, but also how to use the dot product equation to determine how much a vector points in the same direction as another vector, and how to use the cross product to take two vectors and find a third which is at 90 degrees to them. (Ie, the normal of a triangle, if given two sides of the triangle for the vectors.)
And that's just the tip of the iceberg. I have a whole text file full of various equations which are useful for making games, but right now they're probably too complicated for you to use if you just learned the distance equation. :-)