RENDERING, SHADERS, GPU compute, & optimization

Manta C++ game engine:

Voxel Renderer Prototype (renderer stress test)

Wrote a quick voxel rendering prototype within my C++ game engine (Manta) as a stress test for the engine’s rendering abstraction layer/API. the demo features chunk LOD swapping, frustum culling, dynamic per-vertex shadow mapping, fog, and subtle world curvature. The highest quality LOD scheme attempts to swap when voxels are 0.5 pixels or smaller. All in all, it performs pretty well with a scene of ~2 billion blocks at 8 bytes/vertex on my system (~1000fps). There is still plenty of room for optimizations as I'm not sorting draw calls or batching distant LODs (octree).

gpu 2d fluid dynamics simulation (game ready)

Raven software - call of duty (2021 - 2024)

Prior to my current employment, I worked at Raven Software as a Software Engineer on the rendering team working on Call of Duty: Warzone.

A few of the features I worked on there include:

Wrote new shaders for bullet trail VFX to replicate the cylindrical “volume” and preservation of energy of a bullet tracer while minimizing rendering cost (Call of Duty: Modern Warfare II - 2022).
Expanded the engine’s large-scale terrain system & associated tooling to give artists more freedom when painting/applying surface materials and material combinations. See this SIGGRAPH 2023 presentation on Call of Duty’s terrain system for more context.
- These developments significantly improved artist workflow efficiency by reducing/replacing the need to use external tools to make hand-authored material transitions/combinations as done previously.
Implemented low-level engine support for new categories of purchasable gameplay content with careful consideration for data, streaming, and rendering constraints.
Made improvements to the runtime image/mesh streaming system for Warzone’s Caldera map. Caldera introduced pilotable airplanes featuring the fastest player-controlled speeds seen in Call of Duty. The improvements involved heuristically prioritizing streaming to assets along the flight path in order to reduce streamer churn.

Manta deferred renderer (2019, project):

This video showcases a custom 3D deferred rendering pipeline that I developed for Game Maker: Studio 1.4 while studying at University. It was created with the intention of expanding the scope of that engine’s limited built-in 3D capabilities.

Using a deferred rendering approach, this video showcases several combined 3D effects such as normal & specular mapping (PBR materials), parallax occlusion mapping (displacement), point lighting, directional lighting, and real-time shadows (toggleable per light emitter).

The shaders for this engine were primarily written in GLSL ES.

This video demonstrates an implementation of cascaded shadow mapping (CSM) to the renderer mentioned above. The transitions between the cascade levels are blended with linear interpolation to avoid noticeable artifacts between the slices.

The implementation also supports a customizable number and resolution of shadow maps. These can be fine tuned for performance and visual appearance depending on project needs.

You can read about cascaded/parallel-split shadow mapping here.

This video demonstrates an extension of the cascaded shadow mapping implementation above combined with self-shadowing parallax occlusion mapping. Note the self-shadowing of the parallax displacement materials in the scene.

You can read more about self-shadowing displacement mapping here.

This video features yet another effect layered into the rendering engine: screen space ambient occlusion (SSAO). The general goal of ambient occlusion is to simulate the effect of indirect, ambient bounce lighting within a scene (particularly in shadowed areas/crevasses).

SSAO is an optimization of conventional AO, using only the cached depth and normal buffers to approximate the “shading” of a given pixel relative to its surrounding pixels in screen space. More about this technique can be found here.

Demo Download:

You can download a demo executable of this engine here: Windows

Note: This engine is currently work in progress, and this demo currently only supports Windows.

Controls:
Movement: W, A, S, D Elevate/Descend: E, Q
Mouselook Toggle: M
Place Point Lights: P
Place Spotlights: V
Place Spotlights (Shadows): C
Clear Lights: Backspace

Vitality (~2016-2020, Manta games):

VIRTUAL REALITY (2021 & 2014, university)

The videos above are showcase a couple VR applications that I have worked on. Both were created using the Unity game engine with the Oculus Rift SDK.