3D Camera in DCC Software

3D Camera in DCC Software

When you bring a camera solve from tracking software into a 3D package like Maya, Blender, or Houdini, you need to set up the 3D camera correctly. The 3D camera must match the real camera's sensor size, focal length, and lens distortion to ensure that CG elements render with the correct perspective. A mismatch in any of these parameters will make your CG look wrong.

Most tracking software can export a camera directly to your 3D application. 3DEqualizer exports to Maya, Nuke, and other packages. SynthEyes has export plugins for everything. The export includes the camera animation, the focal length, and the sensor size. When you import it, the camera should be ready to use. But you should always verify that the settings match what you expect.

The most common mistake is forgetting to set the correct resolution gate. The resolution gate is the rectangle that shows the boundaries of your render in the camera view. If it is set to the wrong aspect ratio, you will render at the wrong size. Always check that the resolution gate matches your footage resolution and that the camera's film back matches the real camera's sensor size.

Depth of field is another important camera setting. Real cameras have a limited depth of field determined by the aperture and focal length. If you want your CG to match the live action plate, you need to set the same depth of field on your 3D camera. This means setting the f-stop and focus distance correctly. Some renderers can also simulate lens effects like bokeh and chromatic aberration.

For anamorphic footage, you need to set the anamorphic squeeze factor on your 3D camera. Most 3D packages have a setting for this. When you render, the image will be squeezed, and it will look correct when desqueezed in compositing. If you forget to set the squeeze, your CG will be the wrong aspect ratio and will not match the footage.