This is a legacy documentation space! Please refer to V-Ray Next for Maya help for most up-to-date information.

This page provides information on the Camera overrides rollout in the Render Settings.

 

Page Contents

 

Overview


The camera options control the way the scene geometry is projected onto the image, therefore changing how the render looks. These attributes override the following:

  • The type of camera used for rendering
  • Enable Depth of Field
  • Enable motion blur effects for the standard cameras in Maya


If you use the VRayPhysicalCamera in your scene, the parameters in this section of the Render Settings are ignored, except for the overscan and motion blur parameters: prepass samples and geometry samples.




UI Path: ||Render Settings window|| > Overrides tab > Camera rollout

 


 

Camera Overrides Parameters


The cameras in V-Ray generally define the rays that are cast into the scene, which essentially is how the scene is then projected onto the viewing screen. V-Ray supports several camera types described below with sample renders in the next section.



Common parameters for Standard, Spherical, Box, Warped spherical,
Cylindrical (point), Pinhole, and Cube Camera Types

 


Camera parameters for Fish eye Camera Type

 


 
Camera parameters for Cylindrical (ortho) Camera Type

 


Camera parameters for Spherical panorama Camera Type

 


The parameters in this rollout are ignored if you are rendering using Physical camera Attributes, with the exception of the overscan and motion blur parameters: prepass samples and geometry samples.

Camera Type – Types of cameras available in V-Ray. You may set your scene camera to be overridden by selecting one of the following: ( For more information, see the Camera Types example or the Camera Types Explained example below)

Standard – Allows for the current scene camera to be used (usually a pinhole camera).
Spherical – A camera with a spherically shaped lens.
Cylindrical (point) – This camera casts all rays from the center of a cylinder. In the vertical direction, the camera acts as a pinhole camera, and in the horizontal direction, the camera acts as a spherical camera.
Cylindrical (ortho) – This camera casts all rays are cast from the center of a cylinder. In the vertical direction, the camera acts as an orthographic view, and in the horizontal direction, the camera acts as a spherical camera.
Box – Six standard cameras placed on the sides of a box. This type of camera is excellent for generation of environment maps for cube mapping and generates a vertical cross format image. It can also be used for generating irradiance maps for GI: First, you would calculate the irradiance map with a Box camera, then save it to a file and finally reuse it with a Standard camera that can be pointed in any direction.
Fish eye – This special type of camera captures the scene as if it is a pinhole camera pointed at a 100% reflective sphere that reflects the scene back into the camera's shutter, as with using a light probe in HDRI photography. You can use the Dist and FOV settings to control which part of the sphere is captured by the camera. Note that the virtual reflective sphere has always a radius of 1.0.
Warped spherical (old-style) – A spherical camera with slightly different mapping formula than the Spherical camera.
Orthogonal – An orthographic camera enabling flat, non-perspective views.
Pinhole – Overrides the scene camera to force it to be a pinhole camera.
Spherical panorama – Spherical camera with independent horizontal and vertical FOV selection that is useful for generating lat-long images for spherical VR use.
Cube6x1 – A variant of the Box camera with the cube sides arranged in a single row. Unlike the Box camera's output, Cube6x1 does not produce an empty space in the output image and is quite useful in generating cubic VR output.

Overscan mode – The ability to render an extra region beyond the specified image resolution.

None – Does not expand the image resolution area.
Equal margin on all sides – Renders an equal overscan area around the image as specified by the Overscan values.
Horizontal and vertical margins – Renders an overscan area along the top/bottom and sides of the image, as defined by the Oversan values which are expanded to two values by this setting. The first value defines the left/right edges overscan area and the second value defines the top/bottom areas of ovescan in the render.
Left, right, top and bottom margins – Renders four user-defined overscan areas around the image. Overscan values are expanded to four independent values, ordered left, right, top, and bottom.

Overscan values – The numerical amount used for the Overscan mode setting.

Overscan units – Specifies the kind of units to be used by the Overscan values setting.

Override FOV – Overrides Maya's camera FOV (field-of-view) angle. Some V-Ray camera types can take FOV ranges from 0 to 360 degrees, whereas the cameras in Maya are limited to 180 degrees.

FOV – The FOV (field-of-view) value to override the Maya camera's own FOV setting. This parameter appears only when Override FOV checkbox is enabled.

Depth of Field – Toggles on or off additional parameters to control depth of field. See Depth of Field Parameters below.

Motion blur – Toggles on or off additional parameters to control motion blur. See Motion Blur Parameters below.

Height – Specifies the height of a Cylindrical (ortho) camera. This setting is available only when the Camera type is set to Cylindrical (ortho).

Auto-fit – Controls the auto-fit option of the Fish-eye camera. When enabled, V-Ray calculates the Dist value automatically so that the rendered image fits horizontally with the image's dimensions.

Dist – Applies only to the Fish eye camera. The Fish eye camera is simulated as a Standard camera pointed to an absolutely reflective sphere (with a radius of 1.0) that reflects the scene into the camera's shutter. The Dist value controls how far the camera is from the sphere's center (which is how much of the sphere will be captured by the camera). This setting has no effect when the Auto-fit option is enabled.

Curve – Controls the degree of warping for a Fish eye camera. A value of 1.0 corresponds to a real world fish-eye camera. Lower values increase warping, while higher values reduce warping. Technically, this value controls the angle at which rays are reflected by the virtual sphere of the camera.

Vertical FOV – Specifies the field-of-view angle in a vertical direction.







Example: Renders of Camera Types


The images below show the difference between the different camera types used in rendering:


 


Standard camera



Spherical camera



Cylindrical camera


 

 


Orthographic cylinder



Box camera



Fish eye camera


 

 

 


 

Example: Camera Types Explained


This example shows how the rays for different camera types are generated. The red arcs in the diagrams correspond to the FOV angles.


 


Standard


Spherical


Cylindrical (point)


 

 

Cylindrical (ortho)


Box



Fish eye 


 

 

 

 

Depth of Field Parameters




 


These parameters, which appear when the Depth of Field option is enabled, control the depth of field effect when rendering with a standard Maya camera. The parameters are ignored if you render with Physical camera Attributes.

Note: Depth of field is supported only for the Standard camera type. Other camera types do not produce the depth of field effect at this time.

 

Aperture – The size of the virtual camera aperture, in world units. Small aperture sizes reduce the DOF effect.

Center bias – Determines the uniformity of the DOF effect. A value of 0.0 means that light passes uniformly through the aperture. Positive values mean that light is concentrated towards the rim of the aperture, while negative values concentrate light at the center.

Get focal distance from camera – When enabled, the focal distance is determined from the camera target. This setting works only with Maya camera types Camera and Aim or Camera, Aim and Up.

Focus distance – Determines the distance from the camera at which objects will be in perfect focus. Objects closer or farther than this distance will be blurred.

Sides – Enables simulation of the polygonal shape of the aperture of real-world cameras. When disabled, the shape used in calculations is perfectly circular.

Number of sides – Sets the number of sides for the polygonal shape of the aperture.

Rotation – Specifies the orientation of the aperture shape.

Anisotropy – Stretches the bokeh effect horizontally or vertically. Positive values stretch the effect in the vertical direction, while negative values stretch the effect in the horizontal direction.

 

 

Motion Blur Parameters





These parameters, which appear when the Motion Blur option is enabled, set values for calculations of the Motion Blur effect.For more information, see the Motion Blur example below.

Camera motion blur – Enables the calculation of motion blur caused by the movement of the camera.

Duration (frames) – Specifies the duration, in frames, during which the camera shutter is open.

Interval center – Specifies the middle of the motion blur interval with respect to the Maya frame. A value of 0.5 means that the middle of the motion blur interval is halfway between the frames. A value of means that the middle of the interval is at the exact frame position. For more information, see the Interval Center example below.

Bias – Controls the bias of light for the motion blur effect. A value of 0.0 means that the light passes uniformly during the whole motion blur interval. Positive values mean that light is concentrated towards the end of the interval, while negative values concentrate light towards the beginning.

General Motion Blur Parameters

These parameters are used whether you are rendering from a standard camera or from a VRayPhysicalCamera with motion blur enabled.

Shutter Efficiency – In real world cameras, the shutter requires some time to open and close which in turn affects the way motion blur looks. This is especially true for lenses with large apertures. To simulate this effect, this parameter controls how the motion blur samples are distributed in the time interval of the shot. A value of 1.000 means that the samples are evenly distributed as if the shutter opens and closes instantly. Lower values produce more realistic results by placing more samples toward the middle of the time interval.

Prepass samples – Controls how many samples in time are computed during irradiance map calculations.

Geometry samples – Determines the number of geometry segments used to approximate motion blur. Objects are assumed to move linearly between geometry samples. For objects rotating at high speed, increase this parameter to get correct motion blur. Note that higher values increase memory consumption since more geometry copies are kept in memory. For more information, see the Geometry Samples example below.






Example: Motion Blur

 

This example demonstrates the various parameters for motion blur.


 


Motion blur is Off



Motion blur is On


 

 

 



Example: Duration


 

The following scene consists of three-frame animation of moving cone. The cone's position on each frame:

 

Frame 0: Left side
Frame 1: Near box
Frame 2: Right side



The following images show frame 1 rendered with different duration values:

 

 


Duration 0.5 (frames)



Duration 2.0 (frames)


 

 

 


 

Example: Interval Center

 

This example demonstrates the effect of the interval center parameter. The scene is a moving sphere. Here are three sequential frames without motion blur:

 

 

 

Here is the middle frame, rendered with motion blur and three different values for the interval center; the motion blur duration is one frame.

 

 

Interval center = 0.0; the middle of the motion blur interval matches the sphere position at the second frame

 


Interval center = 0.5; the middle of the interval is halfway between the second and the third frame

 

Interval center = 1.0; the middle of the interval matches the sphere position at the third frame

 

 




Example: Geometry Samples


 

The following images demonstrate the Geometry samples parameter using the scene from the Duration example. In all the following renderings, the  Duration (frames)  parameter is set to 2. All other parameters are the same as for the previous images. The higher the value for Geometry samples, the more accurate the estimated object motion. However, excessive increase of this value will result in long rendering times.


 


Geometry samples = 2



Geometry samples = 8


 

 

The geometry samples parameter is useful when creating motion blur for complex motions, for example, fast-rotating objects. Here is an example with an accelerating airplane propeller with a blue and yellow pattern:


Geometry samples = 2



Geometry samples = 3



Geometry samples = 6



Geometry samples = 10


 

Note: The number of geometry samples can be controlled on a per-object basis on the Object Properties dialog. This is useful if you need a lot of samples for some objects in the scene (for example, the wheels of a moving car) while other objects can do with fewer samples (such as the car body). Using more samples only where needed saves memory and speeds rendering.