Working with Lights			Camera Mapping
Chapter 8, Multilayer Compositing and 3D Effects

Topics on this Page:

Adding a Camera to Your Scene

Setting Camera Properties

Accessing Cameras and Camera Views

Transforming Cameras

Modifying Motion Blur for the Render Camera(s)

Resetting the Camera

The camera in Reaction is analogous to a physical camera in the real world. Each Reaction node has a camera that outputs a result; this is the render camera. The camera through which you are currently viewing through is displayed in the upper-left corner of the Player.

Note: When using the orthographic camera, you cannot set certain basic camera properties.

Adding a Camera to Your Scene

You can add as many cameras to a scene as you like, and you can view and render your scene from any camera. There are two ways to add cameras to a scene: through the Cameras tab in a Reaction node or through the Tools tab.

Once you've added cameras, you can indicate which camera(s) to use as the render, or active, camera(s). You can designate any number of cameras as active. Active cameras contribute to the composition's output, and is indicated by the white square under the "A" (active) column of the Cameras tab. You can also set the visibility of each camera.

Note: The camera icon is visible only if you have selected Icons in the Render tab of Reaction.

1. In the Schematic view, select the Reaction node.

2. Select the Cameras tab.

3. At the bottom of the Cameras list, click Add.

   A camera is added to the Cameras list.

1. In the Schematic view, display the Group Schematic by double-clicking the Reaction node or right-clicking the Reaction node and selecting Edit Group.

2. From the Tools tab, select Camera from the Reaction folder and drag it to the Group Schematic.

   A camera is added to the Group Schematic and the Cameras list.

   Note: In the Group Schematic, you can parent a camera to an axis, animate its properties using keyframes or expressions, as well as apply tracking and stabilization.

1. In the Schematic view, select the Reaction node.

2. Select the Cameras tab.

3. From the Cameras list, click the white square under the A (active) column beside the camera(s) you want to designate as the render camera(s).

1. In the Schematic view, select the Reaction node.

2. Select the Cameras tab.

3. From the Cameras list, click the square beside the camera and under the V (visible) column.

Setting Camera Properties

Once you've selected a camera, you can set the properties for each camera in your scene.

1. In the Schematic view, select the Reaction node.

2. Select the Cameras tab.

3. From the Cameras list, select a camera.

4. In the Cameras tab, you can set the properties for selected the camera.

   Parameter	Description
   Type	Perspective (default)-- This projection simulates a real physical camera. Orthographic--With this projection, all camera rays are parallel, and objects do not appear to change size as they change distance from the camera. Field of view settings and depth of field settings available from the Render tab have no effect with this projection.
   Focal Length	Sets the distance for the camera's focal point. As the focal distance increases, the field of view decreases, and vice versa.
   Near Plane	Sets the minimum viewable distance from the camera. By default, the near clipping plane is close to the camera. Setting the near plane farther back will hide objects very close to the camera.
   Far Plane	Sets the maximum distance from the camera. By default, the far clipping plane is very far away, so that you can see the entire scene. Setting the far plane closer to the camera will hide objects farther away.
   Time Dilation	Modifies the motion blur that affects layers animated in the scene. You can give the layer the appearance of moving at a different speed than is set for Motion Blur in the Render tab.
   Angle of View	Lets you frame the scene, making objects appear larger or smaller in the frame.
   Input Stream	The input stream selector controls which streams of the Reaction sources are used when rendering through the given camera. You can specify an explicit stream index (Manual mode) or let the ordering of the camera in the camera list control the selection of the stream (Match Out).
   Film Back	Film Gate --The format of the film gate. Horizonal/Vertical Aperture--The height and width of the camera's aperture or film back, measured in inches. The Camera Aperture attribute determines the relationship between the Focal Length attribute and the Angle of View attribute. The default values are 1.417 and 0.945. Film Aspect Ratio-- When the aspect ratio of the film is modified, the horizontal camera aperture is modified. X = Y multiplied by the aspect ratio. The ratio of the camera aperture width divided by the camera aperture height. When changed, it dynamically adjusts the camera aperture width. Lens Squeeze Ratio--The amount the camera's lens compresses the image horizontally. Most cameras do not compress the image they record, and their Lens Squeeze Ratio is 1. Some cameras (for example, anamorphic cameras), however, compress the image horizontally to record a large aspect ratio (wide) image onto a square area on film. The default value is 1. Fit Resolution Gate--Controls the size of the resolution gate relative to the film gate. If the resolution gate and the film gate have the same aspect ratio, then the Film Fit setting has no effect. Film Fit Offset--Offsets the resolution gate relative to the film gate either vertically (if Film Fit is Horizontal) or horizontally (if Film Fit is Vertical). Film Fit Offset has no effect if Film Fit is Fill or Overscan. Film Fit Offset is measured in inches. The default setting is 0. X & Y Film Offset--Vertically and horizontally offsets the resolution gate and the film gate relative to the scene. Changing the X and Y Film Offset produces a two-dimensional track. Film Offset is measured in inches. The default setting is 0.
   Position	Translates the selected camera about the X, Y, or Z axis.
   Rotation	Rotates the selected camera about the selected axis and changes its orientation. Angles of rotation are measured in degrees.
   Pivot	Moves the selected camera's center along the X, Y, or Z axis.

   
   
   

Accessing Cameras and Camera Views

You can see your scene through different cameras and from different points of view. To see different views, you can use the predefined orthographic views or the perspective view. You can also dolly, truck, or zoom those views without affecting of the contents in the scene, including the render camera.

Note: When using any camera, other than the render camera, zooming and panning in the Player is equivalent to dollying and trucking the camera.

The View From menu lets you access each camera and camera view, and is available from both the hardware and software renderer.

• Right-click the Player and select View From > Camera (Shift + 1). If there is more than one camera, each one is listed. To cycle through each camera, press Shift + 1.

• Right-click the Player, select View From and one of the following: Perspective (Shift + 2), Front (Shift + 3), Back, Left (Shift + 4), Right, Top (Shift + 5), or Bottom.

Transforming Cameras

You can transform cameras interactively in the Player or set values in the transformation fields in the Cameras tab--see Transforming Objects.

Note: The camera is initially positioned in Z according to the composition's format.

Note: Interactive transformations are applied using the camera's local axis, but its position is recorded using global coordinates.

You can dolly, truck, and orbit any camera to view your scene from different angles.

Note: Camera movements are not the same as zooming and panning the Player. For example, if you need to view the pixel output of Reaction up close, you should zoom in. But if you want to move the camera itself, you should dolly.

• Hold down the E key and drag up to move the camera into the scene. Drag down to move the camera out of the scene.

• Hold down the W key and drag up, down, left, or right to position the camera.

• Hold down the Q key and drag in any direction to position the camera.

Modifying Motion Blur for the Render Camera(s)

You can modify the motion blur applied to the render camera(s) in your composition. This gives the appearance of movement in the scene relative to the camera--see Adding Motion Blur and Depth of Field to a Scene.

1. Select the Cameras tab.

2. From the Cameras list, select the render camera(s).

3. Under Motion Blur, modify the Time Dilation. A higher value increases the blur effect giving the impression of faster motion, and vice versa.

Resetting the Camera

You can easily reset the camera to its default.

1. In the Schematic view, select the Reaction node.

2. Do one of the following:

   • Press Shift + Home to reset the camera in the current Player.

   • Right-click the Player and select Reset Camera.