Ai Rendering Weirdness

[ascottk]

Well I wanted to get the maya binary animations to use the AI models they were intended for which would be easier for future animators. The builder guard, the city watch, and the thief are pretty much done but there's a strange side effect:

 

The newly revised versions do not render when you look up towards them. I resynced the md5meshes to make sure it wasn't the meshes themselves. I have no idea why the revisions are doing this The fresh md5anims might be the cause although that wouldn't make sense.

 

The copies on cvs do not do this. There are some problems with some of the walking animations and I was fixing those along the way. The Hip joint is to blame because it rotates 360 degrees in the middle of the animation. If you didn't go frame by frame in maya you probably wouldn't catch it. That why some of the AI tend to walk in circles.

 

Well, it's past my bedtime, but I don't know if the maya 7 -> doom 3 importer is doing it or not or some of my conversions have gone awry.

[Solis]

So the bodies normally render fine, but only disappear when viewed at a certain angle?

 

If so, I think it may have something to do with the object occlusion system that makes models automatically avoid being drawn if the engine doesn't think you could see them. From what I can tell, it sets a point or points on the model to use as a guide to determine if you'd be able to see the model or not, and if it those points don't show up on the screen then it doesn't draw the model.

 

This may have something to do with that. It's possible the system used for setting up those points didn't convert correctly somewhere along the line, if nothing else it may be possible to copy them from the original models that dont' have this issue. Chances are it's using the origin as the point of reference for this and looking up too far on the character causes it to think you wouldn't be able to see the model. A lot of games actually do this, if you ever notice models popping in and out at the edges of the screen it's almost always caused by that.

 

Although I'm not sure if Doom 3 uses the same system, this is a bit of a shot in the dark since I can't think of any other reason that would happen. But if someone knows what I'm talking about it might point us into the right direction for a solution.

[Gildoran]

I would assume it has to do with bounds checking. D3 only renders a model if its screen bounds intersect with visible screen/portal space. What do the bounding boxes look like? Try checking with r_showViewEntities to see their bounding boxes. I think r_showInteractionScissors is intended to debug shadow culling, but it may also be applicable to whether or not an entity is rendered on screen.

 

I also agree with Solis that a poorly placed origin might have that effect.

[SneaksieDave]

This is possibly the same thing that causes snow and rain to disappear when looking at certain angles - an apparent optimization that (incorrectly) determines an object's origin is sufficiently out of FOV and therefore stops drawing the object.

 

It's bad. If it's going to make weather change instantly and models to run around body-less, let's hope real hard there's a fix for it.

 

Edit: whoops missed the above post.

[ascottk]

This may have something to do with that. It's possible the system used for setting up those points didn't convert correctly somewhere along the line, if nothing else it may be possible to copy them from the original models that dont' have this issue. Chances are it's using the origin as the point of reference for this and looking up too far on the character causes it to think you wouldn't be able to see the model. A lot of games actually do this, if you ever notice models popping in and out at the edges of the screen it's almost always caused by that.

 

Although I'm not sure if Doom 3 uses the same system, this is a bit of a shot in the dark since I can't think of any other reason that would happen. But if someone knows what I'm talking about it might point us into the right direction for a solution.

I moved the origin slightly above the plane in the idle & walking animation of the thief but I get the same result.

 

I would assume it has to do with bounds checking. D3 only renders a model if its screen bounds intersect with visible screen/portal space. What do the bounding boxes look like? Try checking with r_showViewEntities to see their bounding boxes. I think r_showInteractionScissors is intended to debug shadow culling, but it may also be applicable to whether or not an entity is rendered on screen.

 

I also agree with Solis that a poorly placed origin might have that effect.

It's r_showViewEntitys with a 'y' btw. That and the r_showInteractionScissors didn't reveal anything suspicious.

 

I'll keep looking at it. It only happens when the AI body mesh is in the lower 20% of the screen.

[Solis]

I would assume it has to do with bounds checking. D3 only renders a model if its screen bounds intersect with visible screen/portal space. What do the bounding boxes look like? Try checking with r_showViewEntities to see their bounding boxes. I think r_showInteractionScissors is intended to debug shadow culling, but it may also be applicable to whether or not an entity is rendered on screen.

Ahh, much better explaination than what I wrote, thanks.

 

Hmm, maybe check between the models on cvs and see if their bounding boxes look any different. I wonder if it uses anything else to try and determine whether the model is in the player's view range. Can you see the bounding box around the model as it disappears when you turn in a direction that makes them disappear?

 

I also wonder if there's a way to disable this entirely for specific models, the weather effects may require that since I wouldn't trust the occlusion system to always determine whether you're within range of an outdoor area or not.

[ascottk]

Hmm, maybe check between the models on cvs and see if their bounding boxes look any different. I wonder if it uses anything else to try and determine whether the model is in the player's view range. Can you see the bounding box around the model as it disappears when you turn in a direction that makes them disappear?

The bounding box is still visible. I have the player shadow enabled & it disappears as well.

[ascottk]

Something was wrong with the animations I imported before I went to Alaska. They render correctly now.