> For the complete documentation index, see [llms.txt](https://ipgames.gitbook.io/htrace-wsgi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ipgames.gitbook.io/htrace-wsgi/settings-and-properties/screen-space-lighting.md).

# Screen Space Lighting

### Evaluate Hit Lighting

This checkbox allows HTrace to evaluate lighting at the hit points of screen-space rays instead of relying solely on the previous `Color Buffer`. This option will affect only those hits that have valid `GBuffer` data (e.g., `Lit` shader). In cases where a pixel with absent `GBuffer` data (e.g., `Fabric` shader) is hit, it will fall back to the previous frame. *Note that this does not affect world space rays*.

This option must be used when the `Diffuse Lighting Multiplier` is set to a high value in the `Indirect Lighting Controller` override.

{% hint style="info" %}
This option is generally useful when the `Color Buffer` contains unwanted information. An example is certain post-processing effects or direct lighting contribution of punctual light sources (that are not supported by world space rays yet and therefore may create a mismatch). 
{% endhint %}

### Directional Occlusion

This checkbox enables directional screen space occlusion. It is an enhanced version of ambient occlusion that provides small-scale, per-pixel indirect shadows. It is also used as a guidance factor for the upscaling algorithm, helping to preserve small-scale details.

{% hint style="info" %}
This feature is in an experimental state and is more suited for scenes with a lot of complex geometry where high-fidelity indirect lighting is required.
{% endhint %}