Switch cameras at specific frames

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Question How do I change from one camera to another at a specific frame in a sequence?

Answer

The easiest way to switch cameras in a scene is through passes. You can create as many passes as you wish from the same original scene.

The following example will use a simple scene with two cameras. The first camera is the scene's default camera:
Open an explorer view and expand the Camera Root. Select the Camera and press "h" to unhide it.

  1. Zoom out in an orthographic (Top, Right, Front) viewport, so as to see the camera.
  2. Create a very simple scene animation, with a frame range of 1 to 100: get a sphere and make it bounce, keyframing its translation along the Y axis.
<P>For more information on how to keyframe an object's translation, see the Animating guide, Chapter 2: Animating with Keys.</P>

  1. Create another camera using the Get > Camera > Perspective command in the Render toolbar.
  2. Name this camera "Cam2".
  3. Translate Cam2 so it has a visibly different angle than that of the default camera.

Each Render Pass has its own set of render options and settings. To switch from one camera to another, we define the default camera as the active camera for the default pass, and Cam2 as the active camera for another Render Pass.
<P>Let's create the second pass:

  1. From the Render toolbar's Pass toolset, select Edit > New Pass > Empty (the new pass has now become the current pass in the Pass text box box).
  2. From the new pass' property page, name the new pass "Camera_Pass".
  3. Click the lock icon in the top-right corner of the Pass' property page, to keep it open.
  4. In an Explorer view, click the scope button to change it from Scene to Pass (or use the "a" shortcut key).
  5. In the List folder, you should see both Default_Pass and Camera_Pass.
  6. Click the Default pass' icon, to open its property page.
    Now, with the Camera_Pass property page that you locked earlier on, you now have access to both of the pass' Render Options property pages side by side.
  7. Default_Pass property page > Render Options > Output tab:
    • Set the Start and End Frames to 1 and 40 respectively.
    • Access the Render Options Format tab and ensure that the default Output Camera (named "Camera") is selected.
  8. Camera_Pass property page > Render Options > Output tab:
    • Set the Start and End Frames to 41 and 100 respectively.
    • Access the Render Options Format tab and set the Output Camera to Cam2.
<P>We have just specified which camera will render at what frame. Of course, you can create as many passes as you wish to change camera as often as you like.</P>
<P> 

To view the final result, select Render > All Passes from the Render toolset in the Render toolbar. The rendered sequence willl render every pass you have defined.

 



More Information

You can also use the Mixer as a way of switching cameras, if you so desire, by using a series of constraints or expressions from your source cameras to a master camera.

If you store the expressions/constraints (as well as any camera parameters you are interested in maintaining) in actions on the mixer, you can sequence/mix at will.

The different cameras do not necessarily have to have the same Picture Standard.



References



Applies To: XSI 1.0,XSI 1.5 on NT

Posted: 10/12/2000

This page was last modified 17:20, 7 Dec 2010.
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