“LOD’s” or Level of Detail are created for a single Asset within your Level that swaps between multiple Assets of differing Polygonal Amounts. For this Post I’ll be using a simple Sphere created from Maya 2014. LODs work based on the Distance from the Camera to the Object
1. Create Your Object in your 3D Package. Create your LODs (in the Same Position) This is important because when the object changes LODs if its on a different position it will move as well. So make sure there in the same location. Activating Snap to Grid can make this easier. Save Each out as individual FBX Files. Open UDK.
2. Import your LOD0 (Base LOD, Highest Tri Count), Open its Mesh Editor. Go to Mesh/ Import Mesh LOD. Select FBX Files & Find your LOD1 File/ Open/ LOD Level is 1/ Ok
3. Up the Top you’ll see LOD: Auto, B, 1, 2, 3 so you can Have a Max of 4 LOD Levels. Base being the Highest. Auto will cycle through them based on the camera distance of the Object.
4. You need to set your LODMax Range to something suitable to reduce popping of Geometry & Make it not noticeable. I use 256 for my Object, you might wanna use the same but play around till you get the result you like. you can apply individual Materials to each LOD under the LODInfo.
1. Import a single LOD0 into UDK open the Mesh Editor/ Mesh Generate LOD/ Set Level (Add New) 1, 2, 3/ Set View distance I used 2000 & Allow Pixal Error I left at 1. Once thats done you will see It has added another LOD Level once you select it, it might not be what you want but you can change it denity of the mesh under “Desired Quality” And use Number of Triangle (%), then click Simplify LOD1, 2, 3, 4. You can see that change by Turning on Show Wireframe.
*Tip: I Use Generated LOD’s for Simple Objects BUT for Character, Cars, Guns ect. you should make your own LOD’s since UDK Doesn’t take into account where it should remove the Tris from. It just removes them evenly this might not be Ideal for some Objects.