Class TCastleRootTransform

Determines the headlight look, if we use a headlight (which is determined by the algorithm described at UseHeadlight and TUseHeadlight). By default it's a simplest directional headlight, but you can customize it, and thus you can use a point light or a spot light for a headlight. Just like https://castle-engine.io/x3d_implementation_navigation_extensions.php#section_ext_headlight .

This is never Nil. Assigning here Nil simply causes us to recreate it using the simplest directional headlight.

The main scene of the world. It's not necessary to set this. It adds some optional features that require a notion of the "main" scene to make sense.

The scene you set here must also be added to our Items.

The MainScene is used for a couple of things:

• Determines initial TCastleViewport.Camera (if TCastleViewport.AutoCamera) and TCastleViewport.Navigation (if TCastleViewport.AutoNavigation) properties. This includes camera position, orientation, projection. This includes navigation type (examine, walk, fly), move speed. These follow the X3D Viewpoint, OrthoViewpoint and NavigationInfo nodes defined inside the MainScene.

  Later changes to nodes Viewpoint/NavigatioInfo using X3D events inside MainScene may also influence the TCastleViewport.Camera and TCastleViewport.Navigation. For example in X3D you can animate the Viewpoint position, and it will actually animate our TCastleViewport.Camera position.

  If both TCastleViewport.AutoCamera and TCastleViewport.AutoNavigation are False, none of these things are applied.

• Determines what background is rendered. If the MainScene contains an X3D Background node (or other node descending from TAbstractBackgroundNode), it will be used.

  Otherwise we render a background using TCastleViewport.BackgroundColor.

  Note that when TCastleViewport.Transparent is True, we never render any background (neither from MainScene, nor from TCastleViewport.BackgroundColor).

• Determines whether headlight is used if UseHeadlight is hlMainScene. The value of MainScene.HeadlightOn then determines the headlight. The initial MainScene.HeadlightOn value depends on the X3D NavigationInfo node inside MainScene.

• Determines the main light casting shadow volumes.

• Determines lights shining on all scenes, if TCastleViewport.UseGlobalLights.

• Determines fog on all scenes, if TCastleViewport.UseGlobalFog.

• The screen effects defined inside MainScene (TScreenEffectNode) are automatically used.

• Main scene is informed about pointing device move, even when the pointing device is not over this scene, and this scene is not capturing pointing device events (the scene "capturing" events once you click on it).

Freeing MainScene will automatically set this property to Nil.

Whether the headlight is shown, see TUseHeadlight for possible values.