RenderMan Globals

The Camera panel provides direct controls over the various setting related to the camera, allowing you to enable and disable various features of the renderer. Some features require greater computational time, such as motion blur and depth of field, and demand a higher shading rate.

Depth of Field - Turning this feature on tells the renderer to enable depth of field calculations. This mimics the behaviour of real camera, where objects which are outside the camera's focal point appear blurred. With this enabled, PRMan will automatically use the focus settings associated with the current rendering camera. For effective quality, you should increase the number of pixel samples (in the quality subpanel, and expect longer rendering times.

Focus on Lookat - Enabling this attribute causes the camera's Center Of Interest attribute to be used in computing the focal distance: objects which are close to the Center of Interest will be in clear focus. This is convenient as Maya allows you to edit the Center of Interest via a manipulator. Disabling this attribute means the Focus Distance, Focal Length, and F Stop attributes of the camera will be used to compute the depth of field instead.

Motion Blur - Enabling motion blur causes moving objects to be blurred along their path of movement in order to prevent temporal aliasing and strobing. When using motion blur, you should increase the number of pixel samples (in the quality subpanel), and expect longer rendering times.

Subframe Motion - When this toggle is turned off, MTOR will calculate the positions of all objects only at frame boundary times, and will rely on the renderer to perform linear interpolation of the object positions in order to determine where they are at shutter open and close times. This results in faster RIB generation times, at the expense of less accurate motion blur. Enabling subframe motion will cause MTOR to calculate the position of objects exactly at shutter open and close time.

Blur Camera - When this feature is disabled, the renderer will ignore the movement of the camera when computing motion blur. If you do move the camera and want everything in the scene to blur accordingly, you will need to turn this feature on; however, you should expect this to be a potentially expensive operation since everything in the scene will now undergo motion blurring calculations.

Shutter Angle - This setting is only meaningful when Motion Blur is enabled. It controls how long the shutter is open during a frame. Measured in degrees a setting of 360 opens the shutter for the entire frame. The larger the angle, the greater the blur, which increases render times.

Shutter Timing - This field allows you to control when the virtual camera shutter opens, and is only meaningful when Motion Blur is enabled. The default value Open on Frame causes the shutter to be open from frame to frame + shutterAngle. If you choose Center on Frame, the shutter will be open from frame - shutterAngle/2 to frame + shutterAngle/2. Note that in PRMan, shading calculations occur only at frame open time, and thus shadows and reflection maps will be computed only at shutter open time.

Shutter Config - When a shutter is moving it transfers information to RenderMan about the current frame and thus can be useful to shaders or templates that refer to the RI standard "time" variable. If you are using RIB archives a shutter config of moving limits the usefuless of an archive with motion blur. In this case you should set the shutter config to stationary. Now archives of motion blurred objects can be inserted into the RIB stream independent of current frame. The downside is the shaders or templates that refer to the time variable will not function correctly. This limitation can be overcome by instead referring to the real time information through the shader's formal parameter list and Slim parameter expressions containing a reference to the current frame via $f.

Front Plane - Turning this feature on causes MTOR to insert an additional piece of geometry directly in front of the camera at the front clipping plane. You will need to turn this on if you use RAT light shaders which provide glow effects; by default, a special surface shader ratLens will be automatically attached to the front plane, which will then sample the glowing lights in the scene. If you instead wish to attach your own special shader to the front plane geometry, use the name frontplane on your shader within your Slim palette.

Back Plane - Turning this feature on causes MTOR to insert an additional piece of geometry at the back clipping plane, behind everything in your scene. By default, a special surface shader ratBackplane will be attached, which allows you to sample the environment lights in a scene. If instead you wish to attach your own special shader to the back plane geometry, use the name backplane for the shader name field within your slim palette.