.. _render-cycles-settings-object-subdivision:

********************
Adaptive Subdivision
********************

.. note::

   Implementation not finished yet, marked as an :ref:`Experimental Feature Set <cycles-experimental-features>`


When using the *Experimental Feature Set* the
:doc:`Subdivision Surface Modifier </modeling/modifiers/generate/subsurf>`
gets changed to control the subdivision of a mesh at the time of rendering.
For this, all the other settings are the same except the *View* and *Render* settings.
These previously mentioned settings get removed/renamed and the following settings are added:

.. figure:: /images/cycles_materials_displacement_mod.png
   :align: right

   Subdivision Surface Modifier.

.. rubric:: Preview


Levels
   The levels of subdivision to see in the 3D View,
   this works the same as the *View* setting on the original *Subdivision Modifier*.

.. rubric:: Render

Adaptive
   Use OpenSubdiv to give different subdivision levels to near and far objects automatically.
   This allows nearer object to get more subdivisions and far objects to get less.

   Dicing Rate
      When using *Adaptive* the *Render Levels* property gets changed to *Dicing Rate*,
      this property is used to multiply the :ref:`scene dicing rate <cycles-subdivision-rate>`.

      .. figure:: /images/cycles-displacement-dicing.png

         Subdivision Off/On, Dicing Rate: 1.0 - 0.3 - 0.05 (Monkeys look identical in viewport, no modifiers).

Levels
   The levels of subdivision to see in the final render,
   this works the same as the *Render* setting on the original *Subdivision Modifier*.


Known limitations
=================

- Missing support for UV subdivision.
- Creases do not match Blender creases currently.
- Instanced are currently uninstanced, leading to increased memory usage.
  For those it is better to use non-adaptive subdivision still.
- Multi-view renders can have some inconsistencies between views.
- Editing displacement shaders while using :ref:`True Displacement <render-cycles-materials-displacement-true>`
  does not update the viewport.