II. Looking at Stuff in the Detail Editor
-------------------------------------------------------------------------The Detail Editor is the program that lets you manipulate and modify objects in Imagine. Like the other editors (and any Amiga program, for that matter) Imagine gets input and directions from you by either moving the mouse and clicking it's buttons, or by typing on the keyboard. Most advanced options use pull-down menus to select the function you want to perform. An important trick, especially when you start using Imagine a lot, is keyboard-equivalents. This lets you select menu items via the keyboard, by pressing the right Amiga key along with another letter or number. All of the keyboard equivalents can be selected via pull-down menus, although not all menu items have keyboard equivalents. You'll find that learning the most used commands' keyboard equivalents can save a LOT of time. Its quick and easy to punch right-Amiga-o to zoom your view out; pulling the menu down repeatedly is a pain. A few other commands (especially moving, rotating, and scaling objects) use the keyboard to indicate what you want to do (move, rotate, or scale) while simultaneously using the mouse to control the extent of the transformation.
You can get into it from any point in Imagine by selecting the menu item 'Detail Editor' from the Project pull-down menu. The screen should then split into four smaller windows with a thin status line at the bottom of the screen and another at the top.
When you start up the Detail Editor, you'll see what is known as a "Quad-View." Are four windows labeled "top", "front", "right", and "perspective", which are different ways of viewing the object you are manipulating. It is difficult to manipulate 3D objects with a 2D mouse and a 2D screen, and the tri-view is a compromise that makes the best of these unfortunate 2D restrictions.
The top, right, and front views show you the wire-frame skeleton of the object you're editing. A wire-frame is a view of your object with each edge shown as a line segment. Faces are NOT shown, so the object looks like it's built from pieces of wire that join at the outside edges of the object, hence the name wireframe. Wireframes have two advantages; they are much faster to draw than "solid" models, and since you can see _into_ the object, you can manipulate points and edges on the interior of the object that you wouldn't normally see.
The top, right and front views are just that- a wireframe view of your object shown from the three orthogonal (right angle) directions. There is also a small axis at the bottom left corner of each view that shows the world's X,Y,Z coordinate system. In Imagine, the X,Y,Z is defined just like it is in mathematics- X is left to right, Y is in to out, and Z is down to up. Some 3D programs define Z to be in-and-out, so note Imagine's difference.
There is an absolute "world" coordinate system defined by these axes. You can select "Coordinates" from the Display menu, which will continually display the coordinates of the mouse pointer in the world's X, Y, and Z system. The units that it measures in are arbitrary, but it is often convenient to call them "Imagine Units." Objects tend to be on the order of 10 to 100 Imagine Units in size, since this is a comfortable scale to deal with when we design scenes to be rendered.
There is a grid shown in the three main windows. This grid is used to give you a sense of scale, and can be turned on or off in the Display menu. The spacing between the lines can be set by choosing "Grid Size", also from the Display window. The default is 20, which is a reasonable starting size. Some commands let you use the grid to snap objects to precise locations- these are the most common reasons you want to change the grid size.
The fourth window (with no grid in it) is called the "perspective" window, which allows you to view your object from any direction. You can also change modes to view your object as a wireframe or as a "solid" model, where the faces become opaque so that you cannot see through your object. In this window, you CANNOT manipulate your objects- it is a view only.
Each of the four windows can be quickly zoomed to take up the full screen very easily by merely clicking on the tall narrow box to the left of each view that contains the name of the window. The window will expand to take up the entire screen, allowing you to have a better view of whatever you're working on. To zoom back to the quad-view, just click on the name to the left again. To go immediately from a full screen display of one view to a full screen display of another, you just click the name of the new view to the right. Being able to see all four views at once is often an advantage, but so is seeing a larger, more detailed view. This method allows you to quickly and easily change how you look at your model.
Just to get a sense of how this works, pull down the menu item 'Functions' and select 'Add primitive'. Click on the 'Torus' button and click on 'OK' to accept the default parameters. All this did was make a pre-defined object that we can look at when we manipulate the views.
You should see an object in all four of the windows. This is the same object, just viewed from different directions. Remember the three main views (Top, Front, and Right) all show a WIREFRAME view from their respective directions, so the inside of the doughnut might look very complex.
Perspective, the remaining view, also shows a wireframe view of the doughnut. You can change the view by manipulating the two white sliding boxes on the top and left of the window. The bottom white slider lets you view from different directions AROUND the object. If the slider is in the middle, you're looking at the front. If it's 3/4 of the way to the right, you're looking at the right hand side, and if it's all the way in either direction, you're looking at the back. The vertical slider on the right controls the ANGLE you're looking at the object from. Centered is a level perspective, all the way up gives you a straight-down view, and all the way down gives you a straight-up view. By combining these two sliders you can look at your object from any direction.
You can change the perspective view by selecting 'wireframe' or 'solid' from the Display pull-down menu. Solid takes longer to show your object, but removes the points that are hidden, getting rid of the X-ray wireframe view. A final way of changing the perspective view is by selecting 'shaded' from the Mode pull-down menu and zooming the perspective view to the full screen. This shades the object in false black and white colors which sometimes lets you see the shape of the object more clearly.
There are a few commands that let you change your absolute vantage of your object. You can zoom your view (on all windows) in and out by using 'zoom in' and 'zoom out' from the View menu. This lets you see more of your object at once, or just a certain portion. Each zoom in or out will double or halve the scale respectively. You can also select a numerical zoom by selecting 'set zoom' in the View menu, which allows more precise magnification levels by simply typing in a number. Zoom in and zoom out are often used, so knowing the keyboard equivalents of right-Amiga-i and right-Amiga-o can save a lot of time.
To scroll the views around, you can click in one of the three main views, then use the arrow keys to move the view in whatever direction you like. You'll notice that if you change one view, the others will change as well- all of the views are linked so they show the same volume of space. You can also scroll the view by telling Imagine where you want the view centered. You select 'Re-center' from the View menu and click on where you want the new center of your view to be. Usually you click right in the middle of the object or area you're interested in. The keyboard equivalent of right-Amiga-. (period) is very convenient.
The display that Imagine shows you is very important, as it is your interface in dealing with everything in the program. One important option is found in the Display menu; it is called "interlace". Interlace will change the screen resolution which the display uses. An interlaced screen is 400 pixels high, whereas a non-interlaced screen is only 200. Unfortunately, the interlaced display will flicker on many Amigas. An Amiga 3000 or a "flicker-fixer" equipped Amiga will be able to use interlaced mode without the flicker. The interlaced mode allows much more detail and more precise location of points, so it is by far the preferred mode to work in. Even if you do have a flickering display, it is probably worth the annoyance to have the extra resolution.
A couple ways to reduce the flicker if you have it: you can muck with the monitor's contrast and brightness, or you can change the screen colors using the imagine.config file (see my Project tutorial). My favorite solution is wearing sunglasses- it works very well indeed, and you look cool while using your computer.
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