At this point, you should be familiar with the information covered in the "Image Preparation" and "Image Illumination" chapters. This chapter describes how to render an image, as well as control the parameters which affect how the rendering computations are performed.
Rendering Settings
Depending on the rendering settings, the complexity of the rendering computations can vary greatly. The rendering settings are specified using the menu item "Render -> Render Settings...", which will open the dialog box shown below.
 
The radio buttons under the "BACKGROUND" section control the intensity of the ambient light, the directed light, and the sky gradient. The visual effect of these values is described in the "Image Illumination" chapter. The intensity of each setting increases from left to right, depending on which radio button you pick. The "Directed Light Rot Angle" and "Directed Light Hgt Angle" edit text values specify the source direction, relative to the front view, of the directed light. The rotation angle controls the side-to-side orientation of the directed light source, in which positive is to the right and negative is to the left. The height angle controls the up and down orientation of the directed light source, in which positive is up and negative is down. If this description is not clear, refer to the "Image Preparation" chapter, since these angles are defined the same as those for the eye view direction.
If the "Beep When Done Rendering" checkbox is set, RenderBoy will beep once when the rendering process is complete. This can be useful if your attention is away from the application while rendering is taking place. If you want RenderBoy to keep quiet, un-check this box.
The "IMAGE SMOOTHING" portion of the dialog is used to specify how much to smooth the image. Smoothing is accomplished with a simple pixel averaging technique. Smoothing can reduce the effect of jagged edges caused by the finite size of the pixels on the screen. Although a reduction in the appearance of "jaggies" is good, lots of smoothing can also eliminate some detail. Experiment to decide what you like.
The "RENDER CALCULATIONS" section controls which calculations should be performed while rendering the image. Depending on which calculations are performed, you may see the following special effects: light source object illumination, shadows, spectral reflections, normal reflections, and refractions. It is sometimes desirable to avoid some computations during a test rendering, since this can greatly reduce the rendering time. The render calculation checkboxes allow you to do this without modifying any objects of your design.
The "Normal Reflections" checkbox controls whether or not to perform the reflection computations which can make objects appear as if they are mirrored. Unless this checkbox is set, all objects will appear un-reflective since they will not be allowed to reflect light. If your design doesn't contain objects which reflect light, then the setting of this checkbox doesn't matter.
The "Spectral Reflections" checkbox controls whether or not to perform the computations which compute spectral reflections, or glinty spots. Glinty spots are caused by the partial reflection of light source objects. This checkbox can remove spectral reflections by essentially ignoring these light sources. If your design contains no light source objects or only objects which are zero percent shiny, then the setting of this checkbox doesn't matter.
The "Shadows" checkbox controls whether or not to perform the computations which compute shadows. Shadows are a side effect of the illumination generated by light source objects. This checkbox can remove shadows by essentially turning off these light sources. For this reason, it is usually a good idea to increase the intensity of the directed light if you do not have this calculation checked. If your design contains no light source objects, then the setting of this checkbox doesn't matter.
The "Refractions" checkbox controls whether or not to perform the refraction computations which can make objects appear as if they are made of glass or crystal. Unless this checkbox is set, all objects will appear opaque since they will not be allowed to refract light. If your design contains no objects which refract light, then it does not matter how you set this checkbox. The index of refraction of individual objects can be set as described in the "Modifying Object Behavior" section of the "Object Manipulation" chapter.
Fog Settings
In real life, very distant objects often appear less distinct than close ones. This is especially true when viewing things outside, since there is often a haze or "fog" in the air which obscures distant objects. We can take advantage of this charactertic within rendered images by using it to emphasize depth or distance. Within the context of RenderBoy, fog causes distant objects to blend or disappear into the background. Objects which are close to the viewers location will be clear. More distant objects will blend into the background color, possibly being obscured completely. These fog characteristics are controlled by three parameters. They can be manipulated using the menu item "Render -> Fog Settings...", which will open the dialog box shown below.
 
You can imagine that there is a "fog bank" which is centered at the "eye view target". The eye view target was described in the "Image Preparation" chapter. The first parameter in the above dialog controls the width of this fog bank. This width is in the same units as all of the object dimensions, and it is usually acceptable to set its value somewhere near the overall front to back distance of the objects in your design. The next two values (visibility percentages between 0% and 100%) determine how well you can see through the fog. The "Min Visibility (%)" value specifies how well you can see objects on the far side of the fog bank. The "Max Visibility (%)" value specifies how well you can see objects on the near side of the fog bank. Within the fog bank, the visibility will gradually vary between these two extremes. For example, you will generally want the "Max Visibility (%)" to be large, since on the near side of the fog bank you will be able to see objects fairly well. Likewise, the "Min Visibility (%)" should be small, since on the far side of the fog bank objects will be partially or completely obscurred. The default values (shown in the dialog box, above) will not show any fog, since all visibilities are 100%.
Note that creating fog effects is really only desireable when you are trying to convey depth or distance. If you do choose to show fog, then consider that in real life fog is almost always some shade of gray. To achieve this in RenderBoy, you will need to set the background color of the rendered image to some shade of gray. Also in real life, it is rare to see fog and shadows at the same time, since the fog diffuses the light which would normally create the shadows. In RenderBoy, illumination and fog are independent. Therefore, it is up to you to decide how (or if) illumination should be modified by the presence of fog. Refer to the "Image Illumination" chapter for related information.
Rendering The Image
Once the design is basically complete (not including the addition of light source objects), the next logical step is to define the eye view. How to do this was described in the "Image Preparation" chapter. Whatever is seen in the eye view as a wire frame is what will be rendered.
There are two ways to render an image. In the first method, you use the mouse to drag out a rectangle within the eye view window, and everything within this rectangle will be rendered. First a quick shading will be done with "chunky" pixels, then a full resolution rendering will occur. This is handy, since you can quickly render small areas of your design which may be of interest. Note that since this rendering is done directly onto the monitor and not into an "offscreen graphics environment", some banding of color may be noticable. Also, you cannot save the resulting image.
The second way to render is to choose the "Render -> Render Image" menu item, which will render the entire image using the current render settings. This is the method to use when rendering finished work that you want to save. The finished image will look better than previews in the eye view, since it will be rendered into an off screen graphics environment, then dithered onto the screen. Before rendering, it is usually a good idea to select the "Render -> Estimate Render Time..." menu item. This will estimate the amount of time required to render the entire image using the current design and render settings.
After selecting the "Render -> Render Image" menu item, all windows owned by RenderBoy will be hidden until rendering is completed, and the menu bar will display "Rendering in Progress". While rendering is taking place in the background, you will will have complete access to the Finder, as well as other applications. When rendering is complete, the windows which belong to RenderBoy will reappear, along with the newly rendered image.
Editing/Printing Rendered Images
This version of RenderBoy produces rendered images as standard Macintosh PICT files. Most commercial graphics applications can open, edit, or print PICT files. Even the "SimpleText" application (which came with your Mac) can read PICT files for the purpose of viewing and printing them. SimpleText can also be used to place portions of an image on the clipboard for use by graphic applications which do not support the PICT file interface. Note that if you plan to use SimpleText in this way, you might want to give it more memory using the Finder's "File ->Get Info" menu item.
Rendering Exercises
At this point, you will want to start RenderBoy and open the "Simple design" included in the documentation folder. Hopefully, you haven't modified it.
The eye view and rendered image sizes of this design have been set to 300x200 pixels. This is a pretty good size for experimenting, but if you did want to change the size, you can use the dialog box opened from the "Render -> Image Size..." menu item.
This design has computations for reflections, shadows, refractions, and fog all turned off. As we go, you will turn them on one at a time so that you can see the affect. First, practice rendering a selected rectangle in the "Eye View" window by dragging out a rectangle with the mouse. Notice how the rendering is done in two passes, first a quick but crude pass, then a slower full resolution pass. You can stop this rendering at any time by just clicking the mouse. This is how you can check the rendered appearance of bits-and-pieces of your design, without waiting for a full rendering. To improve the appearance of these quick renderings, you will want to set your monitor (using your "Monitor" or "Monitors and Sound" control panel under the Apple menu) to display as many colors as possible.
Now that you have an idea what the rendering will look like, let's see how long it will take. Choose the "Render -> Estimate Render Time..." menu item. A dialog box will appear which shows the estimated rendering time for the current design. The rendering time will vary depending on the model and speed of your Macintosh.
Next, choose the "Render -> Render Image" menu item to fully render this image. When you do this, RenderBoy will hide all of it's windows and begin rendering in the background. After a few seconds/minutes, the Rendering will be complete, and the windows will reappear along with your newly rendered image, shown below. Yeah, this first image is rather plain looking. The reason for this is that it is just a basic shading - all of the special ray-tracing calculations have been turned off. Let's see what we can do about that.
 
Choose the "Render -> Render Settings..." menu item and a dialog box will appear. Select the "Shadows" checkbox under the "Render Calculations" section. This tells RenderBoy that in the next rendering, you want to calculate and show shadows. Close the existing image window (save it if you want), then render another image by choosing the "Render -> Render Image" menu item. When complete, you should see a new image similar to the one shown below. Each of the objects on the platter is now casting a shadow generated by the light source object hovering above.
 
Now, let's make it look even better. Again, go into the "Render Settings" as before, and this time check the "Spectral Reflections" checkbox. This tells RenderBoy that your next rendering should show spectral refelections, or glinty spots. Render a new image like you did last time. This one will take a little longer, so you may want estimate the render time again. When it's done, notice how RenderBoy has automatically figured out where the shiny spots on all these different objects will be. If you were to move the light source, these shiny spots (and of course the shadows) would move too. Hey, this is quite an improvement!
 
Now, let's make it look even better. Go into the "Render Settings" again and check the "Normal Reflections" check box. This tells RenderBoy to show the refelections of any objects which might be visible in a reflective serface (like a mirror). Render it again - it will take a little longer than last time. Wow, this thing is starting to look real! Notice how each of the objects is reflecting slightly in the plate they are sitting on.
 
Last but not least, you may want to try applying textures to some of the objects in your scene. Textures were described in the "Object Manipulation" chapter. Also, activate the "Refractions" calculations in the "Render Settings" and render it again. This tells RenderBoy to include the calculations for any objects which are prismatic, like glass or crystal. When it's done, notice how the light blue cylinder to the left now looks like glass. The light is refracting right through it! Hopefully, these five renderings will give you an appreciation for how refractions, reflection, shadows, and textures are the ingredients of realism.
 
Now that you are getting the hang of this, you might want to add some fog to the scene! Choose the "Render -> Fog Settings..." menu item, and a dialog box will appear. Change the "Min Visibility (%)" to zero percent, then re-render the image as before. You should notice how the back of the plate has disappeared into a fog bank, and the objects on the plate which are further away are also less distinct. The overall affect is to give the rendering a somewhat foreboding look and feel. Feel free to experiment on your own and make several small changes to the "Simple Design". Render the result each time to understand the affects. The "Menu Functions" chapter is particularly useful as a reference, but experimentation is the best way to really learn the capabilities of RenderBoy.
