H-Trace: GI & Occlusion HDRP

H-Trace system consists of three main parts:

- Global Illumination

- Ground Truth Ambient Occlusion

- Ground Truth Specular Occlusion

All three are rendered in real-time and computed in a single screen-tracing pass with no baking required.

MAIN FEATURES:

- Full integration into the rendering pipeline comes with both Forward and Deferred support, correct interaction with materials and other rendering features. GI can be picked up by Unity’s SSR and therefore bounced lighting is visible inside screen-space reflections. *

- Reflection Probe Fallback gathers data from all probes in the scene and reconstructs global illumination even when the primary source of lighting is obscured or outside the frame. An alternative fallback mode allows to specify a single custom reflection probe. Real-time reflection probes are supported as well.

- Real-Time Specular Occlusion correctly attenuates both SSR and cubemap reflections using Bent Normals & Cones generated in real-time. It can provide occlusion between separate and / or dynamic objects which is impossible with the traditional workflow that requires offline bent normal map baking. *

- Real-Time Ambient Occlusion uses the most advanced GTAO algorithm with multibounce approximation support and correct blending with the main GI effect. It brings up small details but avoids unrealistic over-occlusion.

- Emissive Lighting support makes it possible to illuminate parts of your scene using emissive materials and objects of any shape that can act as actual light sources and cast soft shadows. **

- Infinite light bounces are simulated through a feedback loop. Every frame gathers one more bounce of light.

- Accurate Thickness mode reconstructs true thickness of all visible objects and renders more accurate indirect shadows in comparison to using a single value as a common thickness denominator for the whole scene.

- Advanced Denoising algorithm includes temporal and spatial denoisers equipped with many features for noise reduction and detail preservation. It also supports self-stabilizing recurrent blur.

- Layer Mask allows to exclude objects from processing on a per-layer basis.

- Flexible performance control with multiple parameters helps to find the right balance between speed and quality. Resolution downscale using either checkerboard rendering or half-res output is also available.

Before buying, please, pay attention to the following details:

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* HDRP package must be patched to support following features:

- Forward rendering & Forward materials support

- Interaction with Unity’s SSR (GI visibility in screen-space reflections)

- Ground Truth Specular Occlusion

The patcher is automated and is included in the package.

** It’s not recommended to use Emissive Materials as your primary and only light source in the scene.

H-Trace is a screen-space tracer. Which means it has most of the natural limitations inherent to all screen-space effects. The reflection probe fallback feature must be used to mitigate these limitations.

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Currently tested APIs are: DX11, DX12 and Metal

Currently tested HDRP versions are: 11, 12, 13, 14 and 15.

Currently tested Unity versions are: from 2021.1 up to 2022.2.

VR, Mobile and WebGL aren’t tested yet. H-Trace is not guaranteed to function properly on these platforms, as well as on any HDRP versions and APIs not listed above. However, their support is planned for future updates.

Feel free to use the Unity forum thread and Discord for direct communication and bug reports.