Caustica

Caustica is an experimental ray-traced renderer for Minecraft 26.2's Vulkan backend. It replaces the vanilla world view with hardware ray tracing and NVIDIA DLSS features while keeping Minecraft's familiar UI and gameplay intact.

Caustica is early software. Expect bugs, missing visual cases, and frequent changes while the renderer is being built.

Links

• Discord
• Modrinth
• CurseForge
• Gallery

Features

• Vulkan hardware path-traced world rendering
• DLSS Ray Reconstruction support
• DLSS Frame Generation support (experimental)
• HDR output
• Dynamic entity rendering in the ray-traced scene
• LabPBR-style material support
• OMM (Opacity Micro-Map) + SER (Shader Execution Reordering) optimizations

Requirements

• Vulkan graphics backend enabled
• A GPU and driver with Vulkan ray tracing support
• NVIDIA RTX GPU and supported driver for DLSS features
• HDR-capable display and OS HDR mode for HDR output
• On Linux, an HDR-capable Wayland compositor and a native Wayland session for HDR output
• Install LabPBR resource pack like SPBR for better visuals

Installation

1. Install Fabric Loader for Minecraft 26.2.
2. Install Fabric API.
3. Put the Caustica jar in your Minecraft mods folder.
4. Launch the game with the Vulkan graphics backend.
5. Open Video Settings to adjust Caustica's renderer options.

Usage Notes

• Caustica is client-side only.
• DLSS Ray Reconstruction and Frame Generation require supported NVIDIA hardware and drivers.
• On Linux if Minecraft crashes on startup with stack overflow errors, try adding -Xss2M to the Java args to increase the stack size.
• Use Java args to improve performance. Minecraft Launcher default: -XX:+UseCompactObjectHeaders -XX:+AlwaysPreTouch -XX:+UseStringDeduplication -XX:+UseZGC
• Frame Generation is experimental and needs to be enabled by modifying the configuration file.
• HDR output requires an HDR swapchain and a correctly configured HDR display.
• When HDR is enabled on Linux, Caustica selects GLFW's native Wayland backend automatically. X11/XWayland surfaces generally do not expose the required HDR10/PQ format.
• If Minecraft falls back to OpenGL after a crash, re-enable the Vulkan backend before using Caustica again.

Compatibility

Caustica takes over the world renderer, so other mods that heavily modify world rendering, shader pipelines, post-processing, or the Vulkan backend may conflict. UI-only mods are more likely to work.

Status

Caustica is not a finished renderer yet. Current work focuses on visual correctness, world coverage, stability, and making the SDR/HDR presentation paths behave consistently.

License

Caustica's project-owned source code and documentation are licensed under the GNU Lesser General Public License v3.0 or later. See LICENSE.md, COPYING, and COPYING.LESSER.

Release artifacts may bundle NVIDIA DLSS/NGX SDK components under NVIDIA's own license terms. See THIRD_PARTY_NOTICES.md.

TODO List

• Nether/End sky, weather, volumetric fog/clouds
• NRD + FSR for non-NVIDIA GPUs
• LOD
• ReSTIR