Developing open world games is hard, not only due to the complexity of the world, but also because when you put something that causes problems into that word, it's quite difficult to pinpoint it afterwards.

During a conference at GDC. CD Projekt RED Senior Technical Artist Martin Thorzén Truu showcased some of those problems, mostly including unoptimized items that were way too heavy on the polycount, others lost under the geometry of the world and more.

Below is what seems to be a monster's nest that hasn't been optimized. It was 52 million polygons...

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The campfire and ship below had most of their polygons sunk under the ground, causing unnecessary load.

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This is a quite costly way to decorate a hamlet, considering the fact that it was 1.5 million polygons.

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In order to solve the problems, CD Project implemented a data base viewer able to identify problematic assets via a series of customizable parameters. You can see it below, and incidentally it also gives us a nice view on part of the map.

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The tool allows for instance to find areas with excessive vertex density (too many poligons) or excessive foliage.

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In this picture, the tool found out a light that cast shadow with a range of 4,000 meters, basically a small sun that bogged down the game.

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This bow was lost under ground.

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The test assets below were nicely hanging around on the map.

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Looks like the folks at CD Projekt had quite some spring cleaning to do. It's hard not to imagine how many of these little mishaps are bogging down the performance of our favorite open world games.