Last summer I got the opportunity to intern at Blizzard and while it’s something that I’ve mentioned, I haven’t really delved into the experience or what I worked on at all.  That is, until now!  Because features I worked on are now shipping and I am super stoked to see them and to share them.

Before I get started, I will say that in the interest of not violating anything I signed with Blizzard, I won’t be talking too deeply about technical implementation.  On the other hand, while I’m very proud of what I did during my internship, none of it is anything I would say is cutting edge and therefore it’s probably pretty easy to replicate without me walking you through it.

So, my internship was as an engine programmer on Team 1 (Starcraft 2/Heroes of the Storm), and my work was primarily in graphics.  I did a wide range of things; working on the core renderer, writing some HLSL, working new features into the art pipeline, and doing a lot of bug fixing.  It was a very rewarding experience, and an amazing time in my life.  One of the bigger features I implemented was occlusion based unit outlining, and it’s something that’s seeing pretty widespread usage in the Heroes technical alpha right now.

The concept here is pretty straight forward.  Designers wanted to be able to tag objects as occluders or occludees (or neither), and then have any portion of an occludee that’s occluded by an occluder be outlined.  And they wanted it done in team color.  Up to this point I hadn’t ever used the stencil buffer in my work, but I was familiar enough with it to see it as a logical choice to handle this.  Occluders and occludees were each masked with different bits of the stencil buffer, the blur would then mask a third stencil bit, and the final copy/resolve would only operate where there was an overlap of the occluder/blur bits and no overlap with the occludee bit.  That made the effect work, but there were a lot of additional considerations in regards to performance and how much it actually helped players that I won’t really be talking about.  And that may or may not be that interesting anyway.

Here’s a video where you can see my effect in action!

While I worked on a lot of other things during my internship, that was by far the biggest feature, and the one I can most readily point at and say, “I did that!”.  And it’s shipped.  I cannot stress enough how rad it is to see something I did be so prevalent in an amazing game like Heroes of the Storm.

So, that’s it for Blizzard work.  I have a number of posts to make about work on my own renderer, and those should be coming soon.  I made a lot of fixes, tweaks, and updates to shaders and general math that improved things a lot in the final month or so of the semester and I’m pretty excited to share them as well.  But, I’m also just getting started with summer classes to finish out my degree, so it might be a little while before I get them written up.  We’ll see!