Class TCastleScreenEffects

Valid only between Render and RenderOverChildren calls. Tells whether we actually use screen effects, thus RenderWithoutScreenEffects renders to texture. Read-only in descendants.

Descendants with special rendering code should override this, and never override Render or RenderOverChildren (as those two methods have special implementation in this class).

This rendering method will be called regardless if we have or not some screen effects. When no screen effects are actually used (e.g. AddScreenEffect wasn't used, InternalExtraScreenEffectsCount is zero), then our Render trivially calls this method without doing anything else.

Add or remove a ScreenEffect node that defines new shader screen effect. See https://castle-engine.io/x3d_extensions_screen_effects.php .

In the simple case, you can pass here an instance of TScreenEffectNode. In a general case, you can passs here any X3D node you want, just remember that only the TScreenEffectNode inside will be rendered. You can e.g. pass a TGroupNode with TScreenEffectNode and TTimeSensorNode as children, and use TTimeSensorNode to provide time to your shader uniform parameter. Or you can e.g. pass an X3D graph loaded from X3D file using X3DLoad.LoadNode, this way you can define effects inside an external X3D file, e.g. like this:

ScreenEffects.AddScreenEffect(
  LoadNode('castle-data:/screen_effects_scene.x3dv'));

If you're looking for inspirations what to put in screen_effects_scene.x3dv, see https://github.com/castle-engine/demo-models/tree/master/screen_effects . See also CGE example in "examples/screen_effects_demo/" directory ( https://github.com/castle-engine/castle-engine/tree/master/examples/screen_effects_demo ) that shows more screen effects code, and shows how to load or construct X3D node graph with ScreenEffect.

The memory management of the node added here is automatic: the added screen effect becomes owned by the internal X3D Group node. It's reference-count is increased at AddScreenEffect, and decreased at RemoveScreenEffect, and it is automatically freed when reference-count drops to zero.

This means that, if you create the provided Node by code, and don't add it anywhere else, then the node will be freed automatically at our destructor (if you call AddScreenEffect and do not call RemoveScreenEffect on it), or at RemoveScreenEffect call. If you don't want this, use TX3DNode.KeepExistingBegin to manage the node destruction yourself.

Note that the given Node should not be used by other TCastlScene instances. In general, a node should not be present in more than one TCastlScene instance, and we already insert the node into an internal TCastlScene instance. Use TX3DNode.DeepCopy if necessary to duplicate node into multiple scenes.

Note that you can enable/disable the effect using TScreenEffectNode.Enabled, or enable/disable all using ScreenEffectsEnable. You do not need to remove the node by RemoveScreenEffect if you only want to disable it temporarily.

Make the screen effects rendering resources ready (e.g. link shaders).

Scale time passing inside TimeSensor nodes you add as part of AddScreenEffect. May be 0 to stop time passing. This has deliberately long name, instead of simple TimeScale, to make it clear that it's completely independent from TCastleAbstractRootTransform.TimeScale.

Enable or disable all screen effects added by AddScreenEffect. When this is True, particular screen effects can still be enabled/disabled using TScreenEffectNode.Enabled. When this is False, all effects are disabled, regardless of TScreenEffectNode.Enabled.