Quartz (2019)

Windows/Linux, C++, Qt, Vulkan, NVIDIA RTX

Physically based Vulkan RTX path tracer featuring a declarative scene description language based on ECMAScript 7.

Quartz is an interactive unidirectional path tracing renderer built on top of Qt 3D near-realtime simulation framework and is powered by NVIDIA RTX technology (via the Vulkan ray tracing extension). It supports rendering of complex 3D scenes and implements a physically based material model with metalness workflow.

The rendering is progressive, meaning that the camera and all scene elements can be updated on the fly while the picture quality improves incrementally when there's no change. Quartz implements a highly parallel architecture that fully utilizes the Qt 3D job system. All scene updates are handled by a collection of fine-grained jobs distributed among many worker threads.

Several techniques for reducing variance have been implemented such as multiple importance sampling (MIS), next event estimation and Russian Roulette path termination.

Features supported by the renderer include texture mapping (albedo, roughness & metalness maps), geometry instancing, directional and area lights (via emissive geometry), IBL environment probes, and depth of field.