Tim Dörries

Rendering Programmer at Epic Games

Epic Games

Biography

Hi, my name is Tim. I am passionate about real-time graphics programming, and like to learn about and implement new real-time rendering techniques that further push the performance and realism of virtual scenes. My real-time rendering journey started with OpenGL 3.3 and OpenGL 4.5, but since then I have come to enjoy working closer to the hardware with modern APIs such as Vulkan and DirectX 12. In my previous role as Software Engineer at skilltree GmbH I was responsible for designing, implementing and maintaining a DirectX 12 renderer for an application for creating digital twins of cities based on map data. Currently I am employed at Epic Games as a Rendering Programmer.

Interests

C++
Modern Graphics APIs (D3D12, Vulkan)
Advanced Real-Time Rendering Techniques

Education

MSc in Computer Science, 2020

Trier University of Applied Sciences
BSc in Computer Science - Digital Media and Games with a major in Games, 2018

Trier University of Applied Sciences

Work Experience

Rendering Programmer

Epic Games

May 2022 – Present Frankfurt, Germany

Software Engineer

skilltree GmbH

Oct 2020 – Apr 2022 Trier, Germany

Responsible for writing and maintaining a D3D12 renderer and collaborating with artists and other engineers to work out desired features and their requirements.

Achievements:

Wrote a DirectX 12 renderer in C++ for an application for generating 3D models of cities.
The renderer is designed around SM6.0 and bindless descriptors, simplifying code and improving performance.
It leverages GPU-driven rendering for batching and culling, enabling the application to render geometry-heavy scenes in real-time.
Features include:
- Dynamic time of day based on latitude, longitude, time and date.
- Atmospheric scattering (realistic, real-time atmosphere rendering) and night sky rendering
- Volumetric clouds
- Tiled/clustered lighting
- IES light profiles
- Histogram auto exposure
- Physically based rendering
- Screen Space Global Illumination
- Screen Space Ambient Occlusion
- Depth of Field
- Temporal Antialiasing

Projects

VEngine 2 (Vulkan/D3D12 Hobby Render Engine)

This is my current hobby render engine that I like to work on in my free time. (C++/D3D12/VK)

VEngine (Vulkan/D3D12 Hobby Render Engine)

This was another hobby render engine that I also used to implement my masters thesis. (C++ and Vulkan/D3D12)

CUDA Pathtracer

A simple pathtracer written in C++ and CUDA.

Experiments with ‘Scalable Real-Time Global Illumination’

An experimental implementation (C++/Vulkan) of a real-time GI technique based on the ‘Scalable Real-Time Global Illumination for Large Scenes’ talk by Anton Yudintsev.

Terrain Editor

A simple terrain editor for creating height maps written in TypeScript and WebGL 2.0.

Separable Subsurface Scattering

Implementation of the Separable Subsurface Scattering technique from http://www.iryoku.com/separable-sss/ in C++ and Vulkan 1.0

OpenGL Hobby Render Engine

This was my first hobby render engine that I also used to implement my bachelors thesis. (C++ and OpenGL 4.5)

Mesh Painter

A proof of concept tool for painting textures in 3D. Uses Qt for the GUI and OpenGL for rendering the viewport.

‘More than Fifty-Two’ (C++)

A C++ rework of the multiplayer card game sandbox which was originially developed with Java.

Implicit Surface Fluid Rendering

Demonstration of a technique for rendering fluids similar to those found in the video game ‘Portal 2’.

PlayStation Vita Rubik’s Cube

A small game that let’s the player solve a Rubik’s Cube on the PlayStation Vita.

‘More than Fifty-Two’ (Java)

A multiplayer card game sandbox written in Java and using a custom OpenGL renderer.

Publications

Tim Dörries

October 2020 Real-Time Volumetric Lighting with Volumetric Shadows

Real-Time Volumetric Lighting with Volumetric Shadows

This masters thesis details the implementation of the popular Volumetric Fog technique for volumetric lighting and expands it with a unified solution for volumetric shadows for both volumes and billboards. Additionally, the checkerboard rendering technique is used reduce the cost of the effect. Written in C++ and Vulkan 1.2.

Tim Dörries

November 2018 State of the Art in Image-Based Post-Processing Effects

State of the Art in Image-Based Post-Processing Effects

For this bachelors thesis, different techniques for image-based post-processing effects (depth of field, motion blur and SSAO) were implemented, evaluated and compared against one another to give an overview of the field and guidance for choosing a suitable technique for a given effect. Written in C++ and OpenGL 4.5.