Level of Detail

Level of Detail objects are created and used to reduce the number of polygons and materials of objects which are drawn in the distance (far away from the camera). 

 

LOD creation rules

* Every object above 300 Triangles must have at least two LODs (LOD0 and LOD1) with LOD1 around 150 triangles. 

• reduce material IDs. more important than removing polygons is the reduction of material ids on your objects. Ideally the last LOD has only one render material ID assigned.
• The difference in polygons from one LOD to the next step should be around 50% (1200 - 600 - 300).
• CryENGINE®2 supports currently up to 6 LODs (this number is hardcoded and might change)

 

General Setup in 3d application

Create reduced versions of the object. Place them in the same position as the original mesh and name them "$lod1", "$lod2", "$lod3". 

Link the objects to the original mesh. Export only the base mesh with the CryENGINE®2 Exporter. The exporter will automatically find the linked LODs and will include them in the .cgf. 

 

• example for linked LODs

 

 

Additionally you can make the lod names a little more specific by adding a SPACE and a descriptive name after the "$lod1"; i.e. "$lod1 box", "lod2 box". 

 

• example of extended LOD names

 

 

LODs can also be created for and linked to subobjects of complex assets,i.e. breakable objects, cars, tanks. 

The engine will then automatically detect the correct LOD step for the subobjects based on distance/size of the object. 

 

• example of LODs for subojects

 

Export

When linked correctly, the LODs do not need to be added to the list window of the exporter. "Merge all Nodes" needs to be unchecked in the exporter settings. 

Old LOD Setup in 3d package (kept for backwards compatibility)

Prepare your assets in the 3d package with the naming convention and export them as seperate .cgfs. 

Add a postfix to the object name to indicate that this object is an LOD for an existing asset. use "_LOD1" for the second LOD and "_LOD2" for the third one. 

Example: ball.cgf 

ball_LOD1.cgf 

ball_LOD2.cgf 

Setup in Sandbox

There is no special setup needed. The Engine will automatically detect LODs and use them if available 

Debugging

 

• e_debug_draw 1 displays the triangle count of the object in view, including the currently active LOD step (if LODs exist)
• e_debug_draw 3 shows color coded LOD steps; blinking objects indicate Objects without LOD