Friday, July 19, 2013

Screens of the day 34 - Fogged

Oh boy, a new screens post! The blog is back on track!

With the latest changes to world scale and the new skybox, I complained about some very ugly artifacts near the far plane when moving around the camera. Let's take this scene as a sample:

You can see the fogged terrain in the background. It looks OK, I won't complain that much about it. The problem is that even moving the camera a few pixels changes the shape of the terrain that intersects the far plane:

As you can see, looking a bit to the right has caused most of the distant landscape to disappear.

Moving yet again causes new terrain to appear.

What is the solution for this? Well probably I am going to need to implement a proper terrain some day, with LOD. Probably geo-mipmapping. Then you can have a lot of low quality terrain in the distance, move the far plane farther away and scale all fog values so that any popping, if it exists, is barely visible because it is so distant. But my terrain implementation is crap and it has a very shitty draw distance.

Like I said in the last post, I can't fix this for now. But I can hack something together just for Snapshot 002 to get rid of the moving far plane artifacts:

OK, view distance is a lot lower, but at least you can't see the artifacts. Let's fine tune the values and see a few more shots:

The only problem is that it does not behave good when looking from high above down:

Oh well, good enough.

I also noticed that the skybox should be rotated, because the light shines from opposite direction as my terrain is illuminated. Wrong :):


Finally, a few posts ago I mentioned that with the freed up resources from simpler terrain rendering, I would either add more materials or implement triplanar mapping. I did some tests with triplanar mapping. I wanted to show some screenshots, but they don't look that impressive. Yes, things look slightly sharper at steep slopes. The effect is expensive, so until I either increase its quality or performance, I won't be using it.

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