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Viewmaps
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.. admonition:: Reference
   :class: refbox

   | Panel:    :menuselection:`Properties editor --> Render Layer --> Freestyle`

.. figure:: /images/render_freestyle_view-map_freestyle-panel.png

   Freestyle panel.

There is only one viewmap per render layer. It controls the edge detection parameters.

Control Mode
   Which detected edges are actually rendered, and how, can be controlled either through:

   Parameter Editor Mode
      The user-friendly :doc:`parameter editor </render/freestyle/parameter_editor/index>`.
   Python Scripting Mode
      Powerful but complex :doc:`Python scripting </render/freestyle/python>`.

View Map Cache
   A option to reuse a previously computed view map for subsequent rendering.
   The cache is automatically updated when the mesh geometry of the input 3D scene has been changed.

   This functionality offers a major performance boost for Freestyle animation rendering
   when camera-space mesh geometry is static, as well as for repeated still renders
   with updates of line stylization options.

   Although the ''View map cache'' checkbox is a render layer option, the cache memory is
   shared by all render layers and scenes. This means that if Freestyle is used for two or more render layers
   (possibly in different scenes through the compositor),
   then the cached view map for one render layer is replaced by a new view map
   for another render layer and hence no performance gain is expected.
Face Smoothness
   When enabled, *Smooth Shading* will be taken into account for edges calculation.
Crease Angle
   If two adjacent faces form an angle less than the defined *Crease Angle*,
   the edge between them will be rendered when using *Crease* edge type selection in a line set.
   The value also affects *Silhouette* edge type selection.
Culling
   Ignore the edges that are out of view (saves some processing time and memory,
   but may reduce the quality of the result in some cases).


Advanced Options
================

.. figure:: /images/render_freestyle_view-map_freestyle-panel-advanced.png

   Advanced Options enabled.


*Sphere Radius* affects the calculation of curvatures for *Ridge*,
*Valley* and *Suggestive Contour* edge type selection in a line set.

Kr Derivative Epsilon
   It provides you with control over the output of *Suggestive Contour* and *Silhouette*
   edge type selection (further information in
   `this pdf <https://wiki.blender.org/index.php/file:Manual-2.6-Render-Freestyle-PrincetownLinestyle.pdf>`__).