HowTo:Add LODs

Editing XMESH

HowTos

Adding Engine Glow

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Levels of Detail, or LODs, are used to help cut down strain on the engine. An LOD mesh is a simplified version of the high-detail (top-level) mesh. When an object is far away from the player, the engine switches to the low-poly LOD so it is easier to render.

It's easy to reference LODs from within the xmesh file of the top-level mesh. All you need to do is place an <LOD> tag somewhere betweeen the <mesh> and </mesh> tags. For example:

<LOD size="275" meshfile="1_1.xmesh" />

Would reference a LOD to replace the current xmesh when the mesh occupies ? pixels on the screen. Size is the perimiter of the pixel dimensions, multiplied by a figure based on the player's detail setting? FIXME - This is really confusing. Also, LODs don't work anymore.

Here is an example of the standard naming scheme for xmeshes:

• name.xmesh = the main mesh
  • 0_1.xmesh = 1st LOD of main mesh
• 1_0.xmesh = submesh #1
  • 1_1.xmesh = the 1st LOD of submesh #1
• 2_0.xmesh = submesh #2
  • 2_1.xmesh = the 1st LOD of submesh #2
  • 2_2.xmesh = the 2nd LOD of submesh #2

and so on.

Note that when creating a BFXM file, only the top level xmeshes need to be appened. For instance, if you are compiling the mesh above, all you need to do is:

mesher.exe name.xmesh name.bfxm xbc
mesher.exe 1_0.xmesh name.bfxm xba
mesher.exe 2_0.xmesh name.bfxm xba

Mesher will automatically append all LODs.

For LODs to work, the entries must be sorted by decreasing size. Basically, "10" means the mesh will be used when it will be drawn in an area 20 pixels wide (10 pixel radius). The numbers must be conservative, meaning they should be a safe transition point where the different between the meshes is barely noticeable, because user detail levels will take care of the rest.

See also

• See Development:Model Guidelines#Polygon/Vertex Count for guidelines on LOD polycounts.
• See Terminology:LODs for a general explanation of LODs.

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Editing XMESH

HowTos

Adding Engine Glow