Chapter 3: Rendering an Object.

To render an object, you need to first have an object or scene created in the Modeler. If you transferred to the Animation program from the Modeler, your file should be displayed. Otherwise, you'll need to load it in. After starting the Presenter 3D program, load your model going to the File menu and choosing Open or by pressing Command O.

After opening the ball created in the Modeler, your screen should look something like that in Figure 3-1.

Image of the Presenter screen
with one object.
Figure 3-1. This image shows 3DJoy's Presenter 3D Animator screen. This is the same object that was created in the modeler. Notice the four different viewing angles.

If your ball is not displayed in the Active Camera window you will need to adjust where the camera is looking. The three windows at the bottom of the screen show the three (orthogonal) perspectives of the scene and include the ball, a sun, and a camera. If any of the windows does not show all the objects, use that window's zoom tool to back up. The perspective of the image displayed in the Active Camera window will change as the camera is moved in any one of the three lower windows. Where the camera points and is focused is determined by a small, movable dot. A line connects the camera to the dot. To move the focus dot, simply click and drag on it. One of the view windows is displayed in Figure 3-2.

Camera focus and direction
Figure 3-2. The camera points in the direction of, and is focused on, the little dot. A line of sight connects the camera to the dot.

The reaction that I first had when seeing my ball was: "What happened? It looked so nice and smooth in the Modeler's Angled window, and now the Active Camera window only shows this blocky thing with lines!"

Never fear, it will be fixed shortly. What is shown in the upper right corner is a Quick Render view. This lets you see an image to get an idea of where things are in a scene and how they will move without having the computer work through the whole detailed rendering (which can take some time with a complex image on an older computer!) There are four buttons to the right of the image that control the degree of rendering displayed in the window. The first button shows boxes representing groups of objects, the second shows boxes for each object, the third shows objects represented with a wire frame mesh, and the fourth shows objects with a filled mesh. How the second, third, and fourth buttons affect the blue ball is displayed in Figure 3-3.

Three images of the Active 
camera window.
Figure 3-3. This series of images shows what the different render quality buttons do.

O.K. so the filled colored ball looks better than the box. It's still not as nice as what was seen in the Modeler. The bad news is that the Active Camera window will never show a higher quality picture than the filled wire frame model. That is not this window's purpose in life.

The good news is that there are two buttons that produce high quality movies and pictures. These buttons are in the upper left corner of the screen and have the movie camera and camera icons. If you press the camera button, a dialog box will appear asking the name and where to save the picture. After clicking on the Render button, a separate window appears. The same dialog box thing happens when clicking on the movie camera button, but this time a series of images are calculated and a QuickTime movie is displayed at the end of the process.

If your being adventurous, you've clicked the camera icon, and what appears in the window? The same blasted rough hewn ball! "Where's my nice ball?!" You're probably thinking at this point. The key lies in the little box just to the right of the camera button. This box is actually a pull down menu with four different rendering choices. The choices are: Quick Render, Phong Render, ray tracer, and Auto Stereogram. When you choose the Phong Render or the ray tracer option, then click on the camera, a beautiful ball appears. This ball is much nicer than even the one seen in the Modeler (and there's no grid!)

Close-up of the rendering icons
Figure 3-4. These are the rendering icons. The camera button makes a rendered picture, and the movie camera makes a QuickTime rendered movie.

The Quick Render choice is the quickest to produce but it only gives the filled mesh figure. The Phong Render choice produces a nicely shaded object. The ray tracer option seems to be identical to the Phong Render at this point, but the ray tracer produces a more realistic image by taking into account surface properties such as reflection, transparency, refraction, and other items. These will be discussed in more detail in Chapter 7 when we add more balls to the scene. The Auto Stereogram produces an image hidden in a random dot pattern. People allege that if they gaze at a location behind the image, a 3D image will appear. Personally, I've never, ever, been able to get these type of things to work. The four resulting images are shown in Figure 3-4.

Three images of the Active 
camera window.
Figure 3-5. This series of images shows the different renderings that are produce from: (upper left) Quick Render, (upper right) Phong Render, (lower left) ray tracer, and (lower right) Auto Stereogram.

At this point, with the Phong Render or the ray tracer option, we have rendered a nice object and we could stop there. But there is a really rad feature that I'd be remiss in not pointing out here.

3DJoy has the ability to produce red/blue 3D images, you know, the kinds that you see with the glasses that are red on the left and blue on the right, and are probably best associated with B movies. Anyway, to the left of the rendering choice menu box, is a box that says "mono", click and drag to the Stereo (red/blue) item. Your image in the Active Camera window will have changed to an image made of red and blue wire frame lines. Put on your red/blue 3D glasses (the 1996 National Geographic issue about the Mars Pathfinder rover came with 2 pairs), grab one of the cameras and have some fun! I found that this works best if I use the Active Window in the wire frame mode (third button). If you want to take a picture, be sure that the rendering option box is on Quick Render. Figure 3-5 shows a simple rendered red/blue image.

Three red/blue stereo objects.
Figure 3-6. Put on your red and blue glasses to see the cone, sphere, and cube!

Now that we can make a nicely rendered ball, it's time to do something with it. In the next chapter we'll make it move, and later we'll make it bounce against a floor.


Next: Moving a Ball

Last: Making a Ball

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©1999 Steven Sahyun - sahyuns@ucs.orst.edu