Re: [Nel] Global retriever

[Benjamin Legros]

> I would like to create a simple 3D application using Nevrax and
collisions. I would like to know the way to create a retrieverbank (.rbank)
and a globalretriever (.gr).


It mainly depends on what kind of terrain geometry you use, NeL landscape
(using patches...) or just simple mesh.

For Landscape :
-You should get the build_rbank tool on the CVS in
nel/tools/pacs/build_rbank
-Setup the config file to point on your input and output directories
(containing .zone files)
-Execute the different passes required by the tool
  1. Build tessellation of the landscape
  2. Generate collision surfaces
  3. Build collision files
  4. Link collision in an unique file

 Your rbank and gr should be in the specified output directory


For Collision mesh :
-Get the build_indoor_rbank tool on the CVS at
nel/tools/pacs/build_indoor_rbank
-Design your collision mesh in 3DS MAX, as planes you will walk on (no
walls, only streets, plane edges will constitute the collision walls.)
-All inside edges of the meshes must be invisible, whereas collision edges
must be visible
-You can split the plane in several meshes, or use different material id
(only reserve mat id 666 for special use). Just make sure a surface (e.g.
same mesh and same mat id) doesn't cover itself -- in this case this would
be an issue for collision engine.
-Select in 3DS MAX all the collision mesh you want to export, specify
different instance group names if required for those meshes, and export them
[nel export/export collision]
- .cmb files are saved in the specified directory, they will be used in the
indoor_rbank tool
-Setup the build_indoor_rbank config file to point on the directory you
saved your .cmb files into, use Merge=0, AddToRetriever=1 and launch the
tool. You should get .rbank and .gr files in the output directories.


If you want to mix landscape and indoor collision, it's a bit more tricky :
-Setup an exterior collision mesh in 3DS MAX so that your indoor mesh is
contained by this exterior mesh, give it mat id 666, and link interior mesh
to exterior by snapping entry door vertices together. The door edges, e.g.
the edge we can walk through MUST be visible. Also the instance group name
of the exterior mesh must be the SAME as the indoor mesh that is linked to
(through the door)
-Export all collision meshes (see section above)
-Use the build_indoor_rbank, with Merge=1, MergeInputPrefix=[the name of the
sole landcape rbank/gr], MergeOutputPrefix=[the name of landscape+indoor you
want]
-Launch the tool, you should get a beautiful couple of rbank/gr files...



If you don't use NeL export nor NeL zone scheme, I think it will probably a
bit more complicated (build you own cmb files ?)


You will also find other information in this thread :

http://mail.freesoftware.fsf.org/pipermail/nel-all/2002-January/005621.html



Hope you are not too confused :)
If you encounter problem, don't hesitate

Benjamin Legros
Nevrax France