65 lines
2.1 KiB
Text
65 lines
2.1 KiB
Text
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.. _doc_level_of_detail:
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Level of Detail (LOD)
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=====================
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Level of detail (LOD) is one of the most important ways to optimize rendering
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(and performance in general) in a 3D project, along with occlusion culling.
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The LOD node
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------------
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The ``LOD`` node provides a simple way of automatically switching between visual
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representations as the node gets closer or further from the
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:ref:`Camera <class_Camera>`, in order to increase performance.
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You might:
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- substitute lower poly count meshes
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- swap several separate meshes for a single approximate mesh
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- swap from a mesh to a billboard
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- turn off particle effects, animations, sounds, scripts according to distance
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- entirely remove visuals in the distance
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The ``LOD`` node should be added as a parent to whatever you wish to use to show
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the object, e.g. a :ref:`MeshInstance <class_MeshInstance>`. You can place
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several :ref:`Spatial <class_Spatial>` derived nodes as children.
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.. image:: img/lod_node_scene.webp
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The ``LOD`` node will automatically hide and show Spatial children depending on
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the distance from the ``Camera``.
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.. tip::
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You can react to ``NOTIFICATION_VISIBILITY_CHANGED`` in scripts to detect
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when a node has been shown or hidden.
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Children are shown in order with the first children shown when closest to the
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``Camera``, and the latter children shown when further away.
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You can determine the distance at which these swaps occur by setting the
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**lod_range** property of ``Spatial``.
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.. note::
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Children of the ``LOD`` node can in turn have any number of children, of
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any type. These grandchildren will inherit their visibility as the ``LOD``
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node operates.
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One of the most common cases is to swap between high-poly and low-poly models.
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.. figure:: img/lod_wireframe.webp
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:align: center
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:alt: From most detailed (left) to least detailed (right), wireframe view
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From most detailed (left) to least detailed (right), wireframe view
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.. note::
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Godot 3.x does not currently generate decimated meshes for you.
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You are advised to generate several versions of a mesh in your
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modeling program (e.g. using the Decimate modifier in Blender).
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