Autodesk 24000-000000-9860 - Revit Architecture - PC, User Manual

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Render Performance and the Building Model
One of the most effective ways to reduce the amount of time required to render an image is to reduce the
number of model elements that the rendering engine must consider. Use one or more of the following
strategies.
Hide unnecessary model elements
For example, if a rendered image will not show furniture that exists on the far side of an interior wall, hide
the furniture in the view before rendering. By doing so, you reduce the number of elements that the rendering
engine must consider during the rendering process. See
Hiding Elements in a View on page 160.
Change the detail level
Change the view’s detail level to coarse or medium. By reducing the amount of detail in the 3D view, you
reduce the number of objects to render, and thus reduce render time. See
Specifying the Detail Level for a
View on page 504.
Reduce the view area to render
Render only the part of the 3D view that you need to show in the image, omitting areas that are not required.
You can do this using a section box, a crop region, the camera clipping plane, or a render region. See
Defining
the View Area to Render on page 1161.
Render Performance and Lighting
The rendering process involves the simulation of light interactions with materials. As a result, render
performance is significantly affected by lighting calculations. When preparing to render an image, consider
the following.
Number of lights
Render time is directly proportional to the number of lights in the scene. In general, mental ray requires
more time to render more lights. Consider turning off lights that are not required for the rendered image.
See
Turning Lights On and Off on page 1139.
In general, an interior view takes longer to render than an exterior view. An exterior view with no natural
light (that is, at nighttime) that shows many interior lights turned on takes a long time to render.
Light source shape
More accurate lights require more render time. The Emit from Shape setting for a light source can impact
render time. For example, point lights render faster than the other shapes. Line lights are slower. Rectangle
and circle lights are slowest to render. See
Defining the Geometry of a Light Source on page 1117.
Soft shadows
Revit Architecture uses area light sources to produce more realistic images. However, area shadows are
expensive to compute. If you increase the quality of soft shadows, render time increases. (In the Render
Quality Settings dialog, use the Soft Shadow options. See
Render Quality Settings on page 1163.)
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