Do We Make Use Of Channels In Our Animations?

[Springheel]

In Doom 3, there are 4 different animation channels ("torso", "legs", "head", "eyelids") as well as a fifth pseudo channel ("all"). A different animation can be playing on each animation chanel simultaneously. This avoids the quake 2 "running while firing" problem, as well as the quake 3 "my model is in pieces" problem. There is one single mesh, but each animation affects a different set of bones. All of this is handled in Anim_Blend. It also handles blending between two completely different animations (for example when you switch between weapons).

 

Are we designing our animations using these channels?

[Ishtvan]

I dunno about the animations, but we certainly make use of them in the scripts and def files. I don't think it's exactly something you specifically design for in the animations, but you can take the animations and play them only on certain channels in the scripts (and these channels are defined within the def files). The walk animation for example is played both on the legs channel and the torso channel. If we wanted them to walk while doing something else with their hands, we could just play another animation on the torso channel while keeping the walk playing on the legs channel.

 

I've never been quite sure if the channels were set up properly for our AI, but that bug where they are "power walking" seems to indicate that the channels are set up correctly, if a bug in the script can make them play the walk animation on the legs and the run animation on the torso/arms.

[Springheel]

If we wanted them to walk while doing something else with their hands, we could just play another animation on the torso channel while keeping the walk playing on the legs channel.

 

So it doesn't matter if the animation was created for just the torso or not, we can choose to play just that part of it?

[Ishtvan]

I believe that's how it works, yes, but it would be nice to get some confirmation of that from somewhere. (I.e., I believe it only plays the animation on the joints defined in the channel, even if the original animation animated joints outside the channel)

[Springheel]

That would be the most versatile system, so hopefully that's how it works.

 

Any ideas how we tell AI when to use different animations for different channels? Frex, currently the builder guard stops running in order to swing at you--how would we tell it to keep playing the running animation for the leg channel and only use the torso for the attack animation?

[Ishtvan]

Any ideas how we tell AI when to use different animations for different channels? Frex, currently the builder guard stops running in order to swing at you--how would we tell it to keep playing the running animation for the leg channel and only use the torso for the attack animation?

 

I'm not sure, I'd have to look at the scripts. I think you would go into the "attack" animation state defined in the script, and tell it to only play the attack anim on the torso channel rather than playing it on both torso and legs. I'm not sure if you have to explicitly tell it to keep playing the walk/run animation too or not, depends on how the states are set up.

 

It might look kind've weird to do it that way though. IMO people who want to attack and gain ground at the same time usually do it by lunging/jumping/charging forward in a more sudden and committed manner rather than simply running as normal and attacking with the arms.

[Domarius]

This is a coding thing. Once the animations are in Doom 3, it can play the head, torso, and legs seperately from each other, as shown by the "jive walking bug" video. No changes have to be made to the anims, the code just has to make use of this feature.

 

I think it would be a good idea to let the guards play the slash anim while they run. We want them to be able to do this, and creating another animation for this is no priority right now, especially when we have this channels feature.