Making an Object Movie in VR Worx

The Setup

To demonstrate a number of approaches to QTVR imaging, I will be showing how to use a DV video camera to capture the images for a QTVR object, so the following description of object movie making assumes you have a specific setup. The setup used in preparing this project includes:

• A homemade turntable for rotating the object 10° at at time
• A DV camcorder connected to a
• Computer
• With a Firewire cable
• Our object, sitting on the turntable in front of
• A neutral backdrop

Shooting and Making a QTVR Object

Feel free to download the images used to make the QTVR object movie in this project for your own practice: Feel free to download the images used to make the QTVR object movie in this project for your own practice: ObjectMovieSource.sit.

Because I am describing a method using a video camera for grabbing images, the steps for making a QTVR object using images on file differs in several places for the following description. The process for acquiring images on file for object movies is very similar to the steps described above for creating the panorama in the scene.

1. Take some special care in positioning your object in the very center of the turntable, otherwise it will walk out of frame when rotated for QTVR imaging. You can check the positioning by framing in the camera and rotatining it 360°.

2. Launch VR Worx 2.0. On the Welcome window select Object under Select document type and click "OK."

3. The Setup step will appear. Essentially, you will just need to change one setting here. The Source selection should be changed to "Video Digitizer." (Use "Image File" for the downloaded images.)
   The defaults for the other settings are correct for this particular shoot, but you should know what a few of them are about:

• Image Size: DV video is good up to about 640 X 480 pixels. Clarity suffers with settings much higher that that. We use 320 X 240 to keep the file size down.
• Vertical Settings: If you have a special QTVR object rig that lets you swing the camera around the object vertically, you would set the number of rows for the number of camera angles you will be shooting from. The sweep it the total angular swing you will be making in the vertical plane.
• Horizontal Settings: This is the number of shots you take for each row (camera angle) for the rotation of the object in the horizontal plane. Typically this is 36 (Columns) in a full 360° sweep, giving 10° of rotation (Spacing) between each shot. This will give you a smooth rotation of an object. You can use fewer shots for a smaller files size, but with a jerkier rotation.

  After making your one change, click on the Acquire tab to go to the next step.

4. The Acquire step is were you bring in your pictures to create the QTVR object. (If you want to acquire images from disk, see how this step works for the QTVR panorama, described above.) On the right is a dynamic illustration indicating your camera angle and the turntable position. Below that is a picture strip (or a picture matrix for multi-row objects) that will show thumbnails of your shots as they are brought into the program. You will first want to check the framing of your picture by clicking on the "Framing" button under Commands.

Setting Manual Exposure

5. The Object Framing window will let you accurately align your object in the camera lens. Use the grid to help you align your camera. Since you will want to capture as much detail as possible, it will help to zoom in to make the object fill the frame.
   You will also want to manually set the exposure. Manual exposure is good for QTVR object photography, because the changes in exposure the camera's automatic exposure gives you may cause a flashing in the object movie when played back. Press the Manual Exposure Button on the Sony DV camera so that the Exposure Meter Bar shows up in the LCD viewfinder. Then rotate the Exposure Setting Wheel until you get the optimal exposure (see figure above). Judge the best exposure in the Object Framing window (not the camera LCD viewfinder!).
   Now you are ready to take the pictures. Click on "Done" in the Object Framing window.

6. There are three options for taking pictures with the video digitizer.
   If you click on "Snapshot" a single picture will be grabbed from the video input and place in the picture strip.
   If you click on "Interactive" you will get a dialogue box that has a video display of what the current camera input looks like and a button for grabbing frames. The Interactive window also displays a countdown display for the number of shots you have taken.
   I prefer the "Rapid Grab" option, which automatically takes shots at your specified time interval. Click on "Rapid Grab" to see the Rapid Grab window. It shows how many Frames to capture and the Delay between frames in seconds. You can change either of these values according to your needs. The computer will emit an audible camera "click" when as each picture is taken. You should rotate the turntable clockwise one increment as soon as you hear each click. When you are ready to proceed, click on "OK" and listen for the first click.

7. As each picture is taken, you will be turning the object 10° clockwise. A thumbnail of picture will appear in the picture strip at the bottom of the Acquire window. When all of the pictures have been taken, click on the Compress tab to go to the next step.

8. You have a number of choices as to the specific video codec you can use for the video compression of your QTVR object movie, but the default setting (Photo-JPEG at Normal Quality) is a good one. Click on the "Compress" button to make your QTVR object movie. Then click on the Playback tab to go to the next step.

9. At the Playback step you have the opportunity to change some of the features of the QTVR movie before exporting it from VR Worx. You can specify the frame of the movie that will show when it is first opened by rotating the movie to that frame and clicking on the "Set" button under Initial View. Some other settings you may wish to make include:

• Annotate: by clicking on the "Annotate" button you can add Name, Copyright, and Description to the movie data. This information can be viewed in applications like QuickTime Player.
• Animation: By clicking on the "Animation" button you can add frame animation to the QTVR object movie. This will cause the object to rotate when the movie first opens. The frame animation will continue until you start interacting with the object movie by clicking on it. Then you can rotate it normally "by hand."
• Playback Window: You can change the dimensions of the movie's playback window. This makes sense if you, say, shot the movie at 640 X 480 pixels and wanted to display it at 320 X 240 pixels. All the detail carried by the 640 X 480 pixels will still be there. This will enable the user to zoom in on the object quite a bit before it gets fuzzy due to pixel interpolation.

Now you are ready to save the Worx document and export your QTVR object movie. Select "Save" from the "File" menu.

10. Give the document an appropriate name, then navigate to the folder where you wish it to be saved and click on "OK" in the dialogue box. Notice that is is a VR Worx document and not a QTVR movie. The QTVR movie which we will export in the next step is the media you will use on a web page or a HyperStudio stack. The VR Worx document contains all the work you have done in Worx heretofore, and contains within it the individual pictures that make up the object movie, as well as the QTVR object movies and all the settings applied to it. It is a fairly large file—12.2 MB—as compared with the QTVR movie we will export out of the Worx program, which is 396 KB. Click on the Export Movie... button in the bottom left corner of the Playback step to export your QTVR object movie.

11. Worx will suggest a name for your QTVR object movie based on the name of the Worx document. You may change the name, but be sure to retain the .mov file name extension, which identifies it as QuickTime media. Navigate to the folder you wish to save to and click on "Export."