Shell rendering

The shell state of the Hierarchical state override component is a transparency effect. In contrast to see-through rendering, only the front-most layer of objects is visible, akin to opaque rendering. Additionally, the objects' normal appearance can be altered when rendered as shells. The effect is intended for use cases where the user should be visually guided away from non-important parts while still maintaining spatial awareness for the whole scene.

You can configure the appearance of shell-rendered objects via the ShellRenderingSettings global state. All objects that use shell rendering will use the same setting. There are no per object parameters.


The shell rendering effect can't be applied to point clouds.

ShellRenderingSettings parameters

Class ShellRenderingSettings holds the settings related to global shell rendering properties:

Parameter Type Description
Desaturation float The amount of desaturation to apply to the usual final object color, in range 0 (no desaturation) to 1 (full desaturation)
Opacity float The opacity of the shell-rendered objects, in range 0 (invisible) to 1 (fully opaque)

See also the following table for examples of the parameters' effects when applied to a whole scene:

0 0.25 0.5 0.75 1.0
Desaturation Desaturation-0.0 Desaturation-0.25 Desaturation-0.5 Desaturation-0.75 Desaturation-1.0
Opacity Opacity-0.0 Opacity-0.25 Opacity-0.5 Opacity-0.75 Opacity-1.0

The shell effect is applied on the final opaque color the scene would be rendered with otherwise. That includes the tint hierarchical state override.


The following code shows an example usage of the ShellRenderingSettings state via the API:

void SetShellSettings(RenderingSession session)
    ShellRenderingSettings shellRenderingSettings = session.Connection.ShellRenderingSettings;
    shellRenderingSettings.Desaturation = 0.5f;
    shellRenderingSettings.Opacity = 0.1f;
void SetShellSettings(ApiHandle<RenderingSession> session)
    ApiHandle<ShellRenderingSettings> shellRenderingSettings = session->Connection()->GetShellRenderingSettings();


The shell rendering feature carries a small constant overhead in comparison with standard opaque rendering. It is significantly faster than using transparent materials on objects or see-through rendering. Performance may degrade more strongly if only portions of the scene are switched to shell rendering. This degradation can occur due to additionally revealed objects requiring rendering. In that regard, performance behaves similarly to the Cut planes feature.

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