Life got in my way a wee bit lately (a trip back to New Zealand, a Windows 11 update bricking an SSD and finishing up the work year to name a few recent events), though I have been tapping away at StaticRectangle. SSAO I decided to tackle SSAO (screen space ambient occlusion) after reading through the learnopengl SSAO article, it didn’t seem like too much extra work on top of what I had just completed for shadows. ...
I struggled getting shadows working, there was a real moment where I wanted to cut my losses and give up. It was particularly frustrating because shadow mapping itself isn’t a difficult concept to comprehend. You render a depth map from your shadow-casting light’s perspective, capturing what the light sees–and equally importantly, what it doesn’t. Then, while rendering pixels (fragments technically) during the main render pass, you check if that pixel falls within the light’s bounds (based on clipping, range, falloff, etc.). If it does, you transform that fragment’s world position into the light’s space and sample the shadow map. You compare the fragment’s depth (from the light’s perspective) against the stored depth in the shadow map–if the stored depth is less, something closer to the light is blocking it, so that pixel is in shadow. ...
OK, so drawing lines is hard. Well maybe not hard per se, but certainly tedious. Looking into it (starting with Matt DesLauriers’ infamous ‘drawing lines is hard’ article linked above), I had the general gist. To draw the lines I want, the way I want, I need to segment them and render triangles. Like this, kind of… No real surprise there, honestly. Your GPU is a super-powered triangle crunching machine. While line primatives (line-list, line-strip) do exist, they’re not very useful–as far as I can tell. They’re typically aliased, hardware dependent and 1px wide. ...
Before we move on, in my last post I took a detour from the lighting/texturing pipeline to fix some issues in my Transform implementation. The debug scene was helpful for finding and fixing issues with transformations and it inadvertently highlighted a different issue. Multi-Sample Anti-Aliasing Without a technique known as ‘anti-aliasing’ edges can look jagged/stair-stepped because each pixel is either fully inside or fully outside the triangle you’re rendering with no in-between. ...
Far from the first and unlikely the last, I’ve taken a slight development detour. Firstly, I have migrated this dev blog from WordPress hosted by my web host to this statically generated one hosted on GitHub. I won’t bang on about it, but I was finding WordPress quite cumbersome and exceptionally slow—not just to load on the client side, but to do anything with it. It made the blogging process quite frustrating for me. ...