Match Moving

The goal of this project is to learn how to integrate a 3D computer generated object into a live action sequence.

Setup Scene

For this test, I simply threw a few everyday objects on a table. Used a hole puncher to create some high contrast markers to make it easier for the software to track camera motion. Any high contrast points can be used as markers. Naturally occurring markers such as rocks on the ground or rivets on a wall can serve as good markers. I'm simply using the paper hole punches to make this example really easy to track.



Shoot Original Footage

It's important to have camera movement that generates enough difference in the markers to allow better triangulation of the camera's position in 3D space. However, jerky camera movements might cause enough motion blue between frames that the markers can be lost by the software and require manual frame-by-frame tracking.

Most of the example I've seen have the camera orbiting around a relatively fixed point in the middle of the scene. The camera motion is hand held floaty which seems to do two things: 1) Generates enough movement that the markers can be more easily triangulated and 2) Sells the shot by appearing to be more casual.

Camera Properties
Samsung HMX-H304BN/XAA
1.8 F Value
30x Optical Zoom Lens
300x Digital Zoom Lens
Schneider Kreuznach Varioplan HD Lens
Lens Focal Length: 2.47 - 74.1mm
Image Sensor:
1/4" (effective size 1/6.3") Image Sensor Size
5M Pixels (1.76M Effective Pixels) Image Sensor
The HMX-H304 is a 1.7-megapixel camcorder with 30x optical zoom and has a 35mm-equivalent focal length range of 38mm-1140mm.

Original video file is HDV_0185.MP4
Video Properties
Dimensions: 1920 x 1080
Codec: H.264 / AVC
Framerate: 60 frames per second
Bitrate: N/A
Audio Properties
Codec: MPEG-4 AAC audio
Channels: Stereo
Sample rate: 48000 Hz
Bitrate: 128 kbps

Convert Footage to Images

ffmpeg -sameq -i ./HDV_0185.MP4 -f image2 chess-%04d.jpg

hmmm… since my source file is already an MP4 format (unlike a previous project which was 3GP) it seems Blender can read in the MP4 file natively. Cool.

Load MP4 into Blender

Alt+A not playing the video frames? Set Playback > check Clip Editors

Sources Introduction to Camera Tracking

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