Thursday, May 10, 2012

Nav-Mesh Editor Part-3

Okay, making more progress on nav-meshes!
New features:
  • Polygon Select Mode
  • Automatic neighbor calculating
  • Path finding preview
  • Nav-Mesh file format ( *.rnm)
I made some more additions to the editor, mostly to make creating these meshes easier. I had to do all the work associated with making a model editor, except my "polygons" can have up to 15 sides ( expandable to 18). All of the navigation data is stored in the one of  the most memory-efficient way possible IMO.

I also got around to making a file-format to store the navigation-meshes in! I call it "Ruined Navigation Mesh" format - original and ironic I know. These files are also VERY size efficient.
For all of you out there familiar with XNA, I've written my own importer and processor...


Header "rNavMesh"
8 bytes
Number of Vertices (v)
2 bytes (ushort)
Number of Polygons (p)
2 bytes (ushort)
12 bytes (float3) * p
0x0C * v * 12
Polygons -
xp vertices ( ushort[] )
yp neighbors ( ushort[] )
Sp = Sp-1 + 4 + xp + yp

Data stored in memory as a single ushort[]

One of the great things about just reading data directly from the file is that XNA can compress *.rnm files automatically!

So in other words, all that's left to do with this is to actually make the meshes, and program some AI to use them :P

Path-finding, Initial Polygons 
Path-finding, Found Path 

Note : Polygons are stored as a single ushort[] in memory, the actual polygon's data is extracted from this array (Yay! bit-wize Shifts)