Create terrain: path mesh vs brushes vs model

[bitterman]

As I think there is a three ways to create a terrain (correct me if I'm wrong):

1. Simple path mesh (bend mode).

2. Brushes.

3. Model (e.g. ASE).

Now I think about next problems:

1) textures & UVW;

2) AAS organization;

3) bot/NPC navigation;

4) animation of walking on uneven/distorted surfaces.

What are the advantages and disadvantages of each way? Any recommendations & tutorials?

Thanks.

[motorsep]

AAS doesn't support meshes, only brushes.

Animation works fine on mesh-based terrains.

There are no bots in Doom 3, but AI navigates using AAS (although it can navigate without AAS, it's better to have AAS).

In Doom 3 mesh based terrain is what you want. You could do brushes, but it's a pain in the ass. Plus performance will suffer if you have crap load of brushes.

Bezier patch surfaces will never give you good terrain.

[bitterman]

AAS doesn't support meshes, only brushes.
...
In Doom 3 mesh based terrain is what you want.

This sounds a bit contradictory. Perhaps you mean mesh which in turn covered with aassolid.

[motorsep]

AAS doesn't support meshes, only brushes.
...
In Doom 3 mesh based terrain is what you want.

This sounds a bit contradictory. Perhaps you mean mesh which in turn covered with aassolid.

No, I mean mesh for terrain and you can block out walkable areas with caulk brushes underneath the mesh (doesn't even need to align with terrain) and use aas* brushes to block off sides/vertical areas (aassolid is for AI to be temporarily blocked or walk on it; I don't think it's what I used in my tests, but I don't remember now what I used)

[The Happy Friar]

I never did the model terrain but I did play with patch terrain in D3 and you have to do the brush+caulk method with it like with models.  It works as expected. 

[BielBdeLuna]

a simpler answer idtech4 from doom3 can't handle complex terrain unless something is added for the AI to navigate it properly

[The Happy Friar]

The AI system doesn't "see" model geometry or curved surfaces.  It can walk on it w/o issues, just doesn't know it's there.  It will be like Doom Q1/2 AI when that happens (which I've used to my advantage, sometimes I didn't want the AI to think, just go to the player).

[BielBdeLuna]

with one exception, AI will never abandon AAS for an unknown area, so you either have a character on the terrain or on the AAS but never on both, it might be that the character starts on the terrain and then afterwards it enters an AAS but he will never leave it. if you want AAS on the terrain then you have to clip the whole navigable area, defeating the purpose of using a terrain mesh. maybe an improvement on the AAS compiler needs to be added in order to make it compile AAS areas for terrain meshes.

[bkt]

huh?

Just put caulk/clip under the terrain and it'll generate AAS that the AI can use to navigate over the mesh.  The AI will see the AAS zones generated by the flat brushes while they will collide with the mesh.

[BielBdeLuna]

it might not be as trivial or easy as this, specially if the terrain isn't flat which should be the point of making any terrain with a mesh.

[motorsep]

it might not be as trivial or easy as this, specially if the terrain isn't flat which should be the point of making any terrain with a mesh.

It's is as trivial as he described and works out of the box.

[bkt]

it might not be as trivial or easy as this, specially if the terrain isn't flat which should be the point of making any terrain with a mesh.

It's is as trivial as he described and works out of the box.

Seconded.

[bitterman]

More info:

http://wiki.thedarkmod.com/index.php?title=Pathfinding

[motorsep]

More info:

http://wiki.thedarkmod.com/index.php?title=Pathfinding

Here is proof it just works (and that map didn't have AAS compiled at all):

[bkt]

More info:

http://wiki.thedarkmod.com/index.php?title=Pathfinding

Here is proof it just works (and that map didn't have AAS compiled at all):

Showing a video that has no AAS compiled is useless as an example.  Without AAS the AI can't see anything in the environment and won't be able to navigate any obstacles, meaning the AI's simply honing in on the players position blindly.

For bitterman:  caulk underneath the static mesh, the AI will see that and navigate over it using the AAS areas generated.  So long as the mesh doesn't exceed an angle the AI can't navigate, then they will be able to navigate effectively.