World of Tanks Gets Ray Tracing Support, But Doesn’t Need Special Hardware

World of Tanks is one of the most popular online games going right now, so it’s notable that it’s soon going to embrace advanced ray tracing – so soon, in fact, that the test can be snagged from the official site right now. Using the enCore RT engine, this WoT update primarily aims to improve shadows around the very thing you will be looking at most often: tanks.

What’s interesting about this ray tracing update is that it doesn’t require special hardware, such as NVIDIA’s RTX graphics cards. It instead relies-upon Intel Embree ray tracing kernels to offload BVH (bound volume hierarchy) work to the CPU so that the GPU can use more of its resources to improve shadows. Intel’s Embree isn’t new, but it does seem to be gaining adoption at a rapid pace lately.

With the 1.0 update of WoT that was released in early 2018, Wargaming overhauled the graphics engine, but didn’t stop its work there. It seems like the company knew about the oncoming demand for ray tracing, and began its preparations for it right away. Things were greatly helped by the decision to leave Windows XP and DirectX 9 in the dust.

Because ideal ray tracing techniques are computationally demanding, tricks have to be used to speed the performance up in real-time games. So, instead of bouncing a hundred or more rays off of a single pixel, models in games are simplified so that the end result will be a rough estimate of what it should look like. With Embree, BVH is done on the CPU to separate triangles into boxes, which are then broken down into even smaller cascading boxes. The GPU will then dig into those so that it can figure out where a light ray’s ultimate destination should be.

What this ultimately means is that instead of needing to consider ray tracing for some 50,000 or more triangles per single tank model, BVH helps reduce the possibilities to a few dozen boxes per tank. Once a triangle is found to intersect with the light source, the (mostly) accurate shadow will then be rendered. Because so few rays are bounced, noise will occur, so a denoiser is implemented to give a suitable end-result.

Because WoT is a competitive game, it seems like most players will relegate ray tracing use to replays, unless their PCs are high-end enough to still deliver great frame rates during gameplay. In addition to using Embree to offload GPU work, Wargaming has put huge work into making its engine process more concurrent data than before, bring forth yet more performance boosts.

As great as this implementation might be, we’d still wager that GPU ray tracing solutions are going to ultimately be the best option in the future, thanks largely to their hugely parallel nature. But even those could potentially make use of Intel’s Embree for some ray tracing work. since our CPUs are (finally) getting bigger. On the GPU side, we know that AMD has ray tracing hardware in the works, and NVIDIA has talked ad nauseam about RTX. It’s still quite nice to see a solution from a big game that will work out-of-the-box. Assuming you have a decent PC, that is. We’re keen on seeing if more developers will jump on the Embree bandwagon in the future.