Compositing your Animation:Master 2000 animation on top of captured video is easy. However, to get a good-looking match in which your 3D character or object really looks like it is in the video scene requires careful control of the video shoot and of how you light and render the animation.

At the Video Shoot:

1. Lock down the camera. When you shoot the background video, put the camera on a tripod or other sturdy support and lock it down so it cannot move. For extra safety, use duct tape or some other means to anchor the tripod to the floor. As long as the camera is steady, you will not have to worry about match-moving your animation to camera movements, shakes, and so on. Match-moving is possible, but it is difficult, so save yourself the trouble, at least for your first tries.

2. Take measurements. Bring a tape measure to the video shoot and measurement how high the camera is from the floor and how far it is from where you plan to place the 3D character or object. Also measure the tilt of the camera using a level or protractor. Finally, note the zoom amount (focal length). You will also benefit from making a little drawing of the scene, noting the location of light sources and shadows and giving some indication of their relative intensity. In fact, you may want to put a real object at the place where you plan to place the 3D character or object and shoot some brief footage of it, to have a record of how the light falls on it and where shadows will be.

In Animation:Master 2000:

3. Use A:M tools to help you place your 3D character or object. Load the video as a rotoscope so you can see how your character will look against the background. This will also allow you to align the choreography grid with the floor or ground in the video to provide an accurate groundplane. Place a flat, square object in the chor for a simple floor, or model and position whatever you need (stairs, etc.) using the video as a reference.

4. Match the camera angle. Using the measurements you took at the shoot, place your A:M camera at the same location in the choreography as the real camera was in the shoot location. Also tilt it to the same degree. FInally, set the focal length of the chor camera to the focal length of the real camera. It will take some experimentation to get it just right. Remember that cameras can tilt too.

5. Match the lighting. This probably the most difficult aspect of the job. Start by thinking about what and where the main light source is in the scene and create that light in the chor. Never make that light pure white--look at the video for a sense of the overall tint of the footage (usually a bit yellowish or bluish) and apply that tint to the main light. Add lots of bounce light from the floor and walls so that your 3D character or object will take on the color of the environment. Remember that light probably varies within the video--there may be pools of light in some spots and areas of darkness in others. If your character or object will move through these areas, you will have to light them accordingly in the chor. I like to use sun and bulb lights for this stage.

6. Match the shadows. Matching the quality and direction of shadows in the video also takes careful judgement. For starters, make sure to create a ground plane large enough to catch shadows from the main light source. In the Properties panel, make the plane a flat-shaded front projection object. Then create a klieg light that casts shadows but no illumination (you can do this by turning diffuse and specular illumination off). This will make the shadows show up on the ground plane even when the plane is flat shaded and will keep the light from adding extra illumination. In the Shadows tab, set the shadow type to Z-buffer soft shadows. Put the klieg where the main light is and set it to Aim At the character or object, so the klieg will follow the character and always cast a shadow. For super-realism but long render times, use ray-traced soft shadows--these emulate real shadows best, because the shadowÕs spread varies with itÕs distance from the object.

7. Match the reflections. If the ground plane in the video is reflective, you will need to make the ground plane in the chor reflective, too. Reflections tend to darken the ground plane slightly, so use them sparingly. Even a light reflection can add a lot of realism to a scene with a shiny floor.

8. Render with grain. Use slight amounts of grain to help tie the character or object into its surrounding. It also helps to soften the image and use depth of field and oversampling. If the footage was shot on video, make sure to render with field rendering to emulate the effect of the 60 fields-per-second NTSC video standard, or the 50 fps PAL standard (you may have to make one test to determine whether the upper or lower field comes first).

--Raf Anzovin

[ HINT  to speed up the interface while animating with a rotoscope that is large you can create a single frame standin version.  You can select between the two on the "Property Page" of the rotoscope (underneath the camera in the Project Workspace tree).  Or you can toggle the existing rotoscope between visible/invisible
Just remember to select the proper rotoscope and settings before starting your final rendering. This will eliminate the loading time required when moving between frames]
 

Fig1: Use measurements of the real set to position the camera as close to the position of the real camera as possible. Then eyeball the rotation and zoom till itÕs just right. In this case, the camera had to be tilted slightly.

Fig2: The large blueish light in this Choreography is the main or key light for the scene, emulating the sunlight coming from an off-screen window (itÕs blueish because of light bouncing from the sky). Smaller yellowish lights surround the character and emulate the effect of light bouncing off the ground and walls. In addition, a klieg light points down from above to emulate the pool of light created by a skylight.

Fig3: The properties panel settings for the ground plane.

Fig4: The only shadow-casting light in this scene is a klieg that is set to do nothing but cast shadows. This allows it to be picked up by the flat-shaded ground plane. An Aim-At constraint keeps the light pointing at the character.

Fig5: The final image. Film grain and softening help to blend it in with the real footage.

You can try this yourself by using these files: Background Footage(20.5MB) Project File
Finished Movie