LOD switching error

praetus

I've created a static mesh with 3 LODs and it works pretty well for the most part but when it switches to the next LOD there is a brief moment when the two LODs are visible and Z fighting with each other and the texture looks as if it goes full bright. As soon as the old LOD cuts out the problem ends. It's for less than second, but when it happens it is pretty jarring and very noticeable.

I've tried to create LODs in max and export them as well as creating the LODs in UDK through the simplygon plugin and they both have the same effect. Has anyone else had this problem and know how to fix it? Is there a way to adjust the amount of time that it takes to transition from one LOD to another?

Any help would be awesome.
[ame="http://www.youtube.com/watch?v=-CjjDc_8O_k"]LOD_Issue UDK - YouTube[/ame]

JamesWild

Had this issue too. Didn't end up fixing it, and just added a very slight push modifier to the lower LODs, which is a terrible workaround. I think the delay is because some meshes can do an intelligent transition, but never found a way around it.

Xendance

Is this realtime?
Enabling "screen door fade" in the material settings of the material applied to the mesh helps too.

praetus

Screen door fade totally fixed the problem. Thanks!

JamesWild

Oh, of course, that makes sense!

Couldn't find a solution during the crunch, thanks, I'll keep that on a mental post-it somewhere.

cptSwing

Yeah, UDK has strange LOD switching.. screen door fade is a little more expensive I think, but there's no alternative really.