[project1dev] Animation LODing

  • From: Alan Wolfe <alan.wolfe@xxxxxxxxx>
  • To: project1dev@xxxxxxxxxxxxx
  • Date: Thu, 7 May 2009 21:41:33 -0700

Ok so for those of you that don't know what LOD is, it stands for "Level of
detail" and in essence means that when things are farther away, or less
noticeable in some way, that you use less detail cause nobody notices, and
that saves you processing power and memory.

For example, objects that are farther away (models, mountains, etc) use less
polygons when they are far away since you can't tell the difference at a
great distance anyways.

It makes everything way nicer.

Anyhow...So animating models is expensive (takes a lot of CPU power).

Today i learned something really bad ass, an animation LODing technique.

So what the deal is, is you declare up front how many of a specific type of
animation are allowed to run at once.

So like... if you have 10 people all walking around using the same
animation, normally you'd have to pay the cost of processing that same
animation 10 times.

The LOD technique is to say "only allow 3 maximum instances of that
animation to happen at once".

So what that does is only process 3 animations but have multiple people use
the same processed animation data.

If you set it to only 1 maximum instance, everyone would animate and walk in
unison which is really crappy, and if you do too high a number maximum
instances, too many people are animating and it eats up a lot of CPU.

So you basically find the balance and say "well its hard to tell that they
are sharing animations if you do 3 max" and then you have your magic number,
and the game runs faster.

It's kind of cool... just wanted to share it with everyone...

Other related posts: