Raster Overlay Doesn't Show Correctly When Too Far

Hello there.
My tile set hide one of its raster overlays if camera is too far from it.

I’m trying to blend 2 heatmap overlay (derived class of raster overlay, providing an image of heatmap) to show a dynamic heatmap.

When camera is close enough to the tile set, it looks good. But when my camera leaves the tile set, some north and east tiles (the “Wrong” part below) only shows heatmap1, while others (the “Correct” part below) still show both.

I’m not sure whether some of the raster overlays’ properties duplicated, so some tiles only render one of them. Or there’s some trouble with MPC instance, because I use MPC in MLB to control the blending.

Please help me. The problem destroyed my whole design.

Thanks,
MuttonYung

What sort of raster overlay component are you using? Is it possible that whatever tile server (TMS, WMS?) you’re using isn’t returning any data for the larger, lower-detail tiles? That’s a pretty common thing for WMS, especially, in order to save the server from processing too much data for a single request.

Thanks for replying. It’s a material problem rather than distance problem.
I use 2 materials to show land and areas with water. But only the land material is correct. When the camera leave the terrain, some parts of heatmap share a tile with the ocean. They use the wrong water material so that they look differently from what I expect.
After I change water area material, everything works well.