Quake II RTX is NVIDIA's attempt at implementing a fully functional version of Id Software's 1997 hit game Quake II with RTX path-traced global illumination.
Quake II RTX builds upon the Q2VKPT branch of the Quake II open source engine. Q2VKPT was created by former NVIDIA intern Christoph Schied, a Ph.D. student at the Karlsruhe Institute of Technology in Germany.
Q2VKPT, in turn, builds upon Q2PRO, which is a modernized version of the Quake II engine. Consequently, many of the settings and console variables that work for Q2PRO also work for Quake II RTX.
Quake II RTX is licensed under the terms of the GPL v.2 (GNU General Public License). You can find the entire license in the license.txt file.
The Quake II game data files remain copyrighted and licensed under the original id Software terms, so you cannot redistribute the pak files from the original game.
Quake II RTX introduces the following features:
- Caustics approximation and coloring of light that passes through tinted glass
- Cutting-edge denoising technology
- Cylindrical projection mode
- Dynamic lighting for items such as blinking lights, signs, switches, elevators and moving objects
- Dynamic real-time "time of day" lighting
- Flare gun and other high-detail weapons
- High-quality screenshot mode
- Multi-GPU (SLI) support
- Multiplayer modes (deathmatch and cooperative)
- Optional two-bounce indirect illumination
- Particles, laser beams, and new explosion sprites
- Physically based materials, including roughness, metallic, emissive, and normal maps
- Player avatar (casting shadows, visible in reflections)
- Recursive reflections and refractions on water and glass, mirror, and screen surfaces
- Procedural environments (sky, mountains, clouds that react to lighting; also space)
- "Shader balls" as a way to experiment with materials and see how they look in different environments
- Sunlight with direct and indirect illumination
- Volumetric lighting (god-rays)
You can download functional builds of the game from GitHub Releases.
- Announcement Article
- Ray-Tracing Deep Dive
- Launch Trailer Video
- Path Tracer Overview Video
- GDC 2019 Presentation
- Client Manual
- Server Manual
Also, some source files have comments that explain various parts of the renderer:
- asvgf.glsl explains the denoiser filters
- checkerboard_interleave.comp shows how checkerboarded rendering facilitates path tracing on multiple GPUs and helps with water and glass surfaces
- path_tracer.h gives an overview of the path tracer
- tone_mapping_histogram.comp explains the tone mapping solution
In order to build Quake II RTX you will need the following software installed on your computer (with at least the specified versions or more recent ones).
Windows | Linux | |
---|---|---|
Min Version | Win 7 x64 | Ubuntu 16.04 |
Note: only the Windows 10 version has been extensively tested.
Note: distributions that are binary compatible with Ubuntu 16.04 should work as well.
Min Version | |
---|---|
NVIDIA GPU driver https://www.geforce.com/drivers |
460.82 |
AMD GPU driver https://www.amd.com/en/support |
21.1.1 |
git https://git-scm.com/downloads |
2.15 |
CMake https://cmake.org/download/ |
3.8 |
Vulkan SDK https://www.lunarg.com/vulkan-sdk/ |
1.2.162 |
- zlib
- curl
- SDL2
- stb
- tinyobjloader-c
- Vulkan-Headers
- glslang (optional, see the
CONFIG_BUILD_GLSLANG
CMake option)
-
Clone the repository and its submodules from git :
git clone --recursive https://github.com/NVIDIA/Q2RTX.git
-
Create a build folder named
build
under the repository root (Q2RTX/build
)Note: this is required by the shader build rules.
-
Copy (or create a symbolic link) to the game assets folder (
Q2RTX/baseq2
)Note: the asset packages are required for the engine to run. Specifically, the
blue_noise.pkz
andq2rtx_media.pkz
files or their extracted contents. The package files can be found in the GitHub releases or in the published builds of Quake II RTX. -
Configure CMake with either the GUI or the command line and point the build at the
build
folder created in step 2.cd build
cmake ..
Note: only 64-bit builds are supported, so make sure to select a 64-bit generator during the initial configuration of CMake.
Note 2: when CMake is configuring
curl
, it will print warnings likeFound no *nroff program
. These can be ignored. -
Build with Visual Studio on Windows, make on Linux, or the CMake command line:
cmake --build .
Quake II RTX supports music playback from OGG files, if they can be located. To enable music playback, copy the CD tracks into a music
folder either next to the executable, or inside the game directory, such as baseq2/music
. The files should use one of these two naming schemes:
music/02.ogg
for music copied directly from a game CD;music/Track02.ogg
for music from the version of Quake II downloaded from GOG.
In the game, music playback is enabled when console variable ogg_enable
is set to 1. Music volume is controlled by console varaible ogg_volume
. Playback controls, such as selecting the track or putting it on pause, are available through the ogg
command.
Music playback support is using code adapted from the Yamagi Quake 2 engine.
When a single player game or demo playback is paused, normally with the pause
key, the photo mode activates.
In this mode, denoisers and some other real-time rendering approximations are disabled, and the image is produced
using accumulation rendering instead. This means that the engine renders the same frame hundreds or thousands of times,
with different noise patterns, and averages the results. Once the image is stable enough, you can save a screenshot.
In addition to rendering higher quality images, the photo mode has some unique features. One of them is the
Depth of Field (DoF) effect, which simulates camera aperture and defocus blur, or bokeh. In contrast with DoF effects
used in real-time renderers found in other games, this implementation computes "true" DoF, which works correctly through reflections and refractions, and has no edge artifacts. Unfortunately, it produces a lot of noise instead, so thousands
of frames of accumulation are often needed to get a clean picture. To control DoF in the game, use the mouse wheel and
Shift/Ctrl
modifier keys: wheel alone adjusts the focal distance, Shift+Wheel
adjusts the aperture size, and Ctrl
makes
the adjustments finer.
Another feature of the photo mode is free camera controls. Once the game is paused, you can move the camera and
detach it from the character. To move the camera, use the regular W/A/S/D
keys, plus Q/E
to move up and down. Shift
makes
movement faster, and Ctrl
makes it slower. To change orientation of the camera, move the mouse while holding the left
mouse button. To zoom, move the mouse up or down while holding the right mouse button. Finally, to adjust camera roll,
move the mouse left or right while holding both mouse buttons.
Settings for all these features can be found in the game menu. To adjust the settings from the console, see the
pt_accumulation_rendering
, pt_dof
, pt_aperture
, pt_freecam
and some other similar console variables in the
Client Manual.
The engine has a system for defining various properties for surface materials, such as textures, material kinds, flags, etc.
Materials are defined in *.mat
files in a custom text-based format. The engine will read all materials/*.mat
files from
the game directory (or directories when playing a non-base game) in alphabetic order, and materials in the later files override
the materials in the earlier files. Then the engine also reads a <mapname>.mat
file when loading a map, and the materials
defined in the map-specific file override global materials - but only those used for map geometry, not models.
The .mat
files consist of multiple material entries, where each entry can define multiple materials. For example:
textures/e1u2/wslt1_5,
textures/e1u2/wslt1_6:
texture_base overrides/*.tga
texture_normals overrides/*_n.tga
texture_emissive overrides/*_light.tga
is_light 1
correct_albedo 1
The above example defines two materials that will be used for surfaces that reference .wal
files with the same base names,
and for each of these materials it defines three textures. The *
symbol in the texture definition is replaced with the
material base name, so either wslt1_5
or wslt1_6
in this example.
When a material is not defined for a surface, the engine will look for textures with matching names and various extensions.
First, it will look in the overrides/
directory, then in the original texture path. Normal maps are searched with the _n
suffix, and emissive maps are searched with the _light
suffix. If no replacement files are found, just the original base
texture will be used.
Materials can also use the automatic emissive texture generation feature. This is the case for undefined materials when the
pt_enable_surface_lights
console variable is nonzero: wall surfaces with the SURF_LIGHT
flag (but not SURF_SKY
or
SURF_NODRAW
) will generate an emissive texture from the base texture and a threshold value, if no emissive texture is found,
and marked with the is_light
material flag.
The threshold value is set using the pt_surface_lights_threshold
variable.
For defined materials you can the synth_emissive
and emissive_threshold
material properties to explicitly enable
emissive texture generation.
Materials can be examined and modified at run time, using the mat
command. For example, mat print
will print the properties
of the currently targeted material to the console. To get more usage information, use mat help
.
The Quake II console can be remote operated through a UDP connection, which allows users to control in-game effects from input peripherals such as MIDI controllers. This is useful for tuning various graphics parameters such as position of the sun, intensities of lights, material parameters, filter settings, etc.
You can find a compatible MIDI controller driver here
To enable remote access to your Quake II RTX client, you will need to set the following console variables before starting the game, i.e. in the config file or through the command line:
rcon_password "<password>"
backdoor "1"
Note: the password set here should match the password specified in the korgi configuration file.
Note 2: enabling the rcon backdoor allows other people to issue console commands to your game from other computers, so choose a good password.
The engine includes support for placing a set of material sampling balls in any location. Follow these steps to use this feature:
- Download the
shader_balls.pkz
package from the Releases page. - Place or extract that package into your
baseq2
folder. - Run the game with
cl_shaderballs
set to 1, either from command line or from console before loading a map. - Use the
drop_balls
command to place the balls at the current player location.