I.
All is not beer and skittles, however. Since it is so all-inclusive, OpenGL is not as fast as, say, DirectX is, since Microsoft can direct the latter against only Windows machines and the OS (which, of course, they know intimately). In fact, OpenGL drivers on many video cards depends on DirectX in their Windows driver versions. Furthermore, video card manufacturers, in order to raise their Duke Nuk'em ratings, have added corner-cutting accelerations to their cards. As long as the scenery is flying by they work great, but in precision CAD work the corner cuttings start appearing as errors - renderings not complete, smearing of textures and so on. Therefore, if such problems are encountered in Punch!, one of our first recommendations is that the accelerations be turned off. The fact that you can turn them off indicates that the manufacturer's know that they will sometimes cause problems. See The Ten Commandments of Punch! Problems, article V.
II.
Where Is LiveView Used? - LiveView is used in many Punch! PowerTools - the Elevation Editor, the Fireplace and Cabinet Wizards, and so on. In all of these except for the Elevation Editor, the views are perspective, and therefore scale changes depending on how far away an object is. The projection in EE is called "isometric", meaning that it is not perspective, and scale has meaning uniformly. However, in an apparent oversight, the EE, like all other uses of LiveView, does not allow for setting the scale. Sorry.
Other things all examples of LiveView have in common: they can all (as of Version 8.0) be exported to a number of graphics formats. The rendering quality is adjustable.
III.
ClearView - LiveView is normally rendered in textures. The textures and colors you have assigned are rendered with shading and shadowing added. However, there is a mode called ClearView in which the edges are rendered as blue lines (a color which is settable) on a white background, known generically as a "wireframe" view. The ClearView slider (available on some, not all LiveViews) allows the user to set a transparency value for the solid surfaces, so that detail behind a wall, for example, can show through. In version 8.0, there are several new ClearView modes: the traditional blue on white with the ClearView slider is there; there is also a mode which displays all the objects in their plan color on a black background, and finally a view with teh object lines approximating their texture color, again on a black background.
ClearView also renders the grid system in the terrain (in versions prior to 8.0), which makes it handy for seeing the grid.
IV.
Navigation - Navigating in LiveView is a challenge for beginners, but one which is easily learned with some practice. It is, however, aggravated by the unfortunate problem of lack of mouse controls. The sensitivity to mouse movement is the same as it was when version 2.0 came out, but hardware has advanced a long way in that time and what was adequate for a 16MHz PII computer is too horribly fast for a PIV 3GHz machine, requiring great patience and very sensitive mouse movements. See The Ten Commandments of Punch! Problems, Article X.
There are basically two modes of navigation, with two more introduced in 7.0. The first two, chosen with the green walking man icon and the green helicopter, are called walk-through and fly-around, respectively. All navigation occurs through mouse movements, with the cursor located on the LiveView window. The two new modes are chosen with the yellow man and helicopter icons. The movements are summarized in this table:
| Green Walker | Yellow Walker | Green Helicopter | Yellow Helicopter | |
|---|---|---|---|---|
| Drag Upwards/Downwards | Advance the viewpoint straight ahead or straight back | Tip the viewpoint upwards/downwards (range limited to +/-45 degrees from horizontal) | Increase/decrease the lookdown angle of the viewpoint (range limited to 0 to -35 degrees) | Decrease/increase the lookdown angle of the viewpoint (note opposite movement from green helicopter) |
| Drag Left/Right | Set the rate of turn to the right/left; the further the movement the faster the turn | Rotates the viewpoint left/right an amount proportional to the drag distance | Sets the rate of revolution around the house in the opposite direction of the movement | Rotates around the house in an amount proportional to the drag distance |
| Hold down Right Mouse Button (the movement toggles each time the button is used) | Move up/down vertically at an even rate | Acts the same as the left mouse button | Move into/out from the center of rotation | |
| Plan Icons | The viewpoint is indicated by a black dot on the plan. The direction the viewpoint is aimed is indicated by an adjacent black solid triangle. The viewpoint may be dragged to a new location on the plan, and the triangle can be dragged around the viewpoint to change the facing direction. | The center of rotation is indicated by a crosshair icon on the plan. It may be dragged to any new location on the plan. | ||
V.
Cutaway Options - Most LiveView windows have a cutaway slider down their left side, which allows the user to make part of the LiveView disappear, giving access to display of internal components of the model. The icon at the top determines the direction of the cutaway; it changes when clicked upon. When the red bar is at the bottom of the icon, the cutaway action develops from the front going back. When the red bar is on the left, then the cutaway action occurs from that direction. Similarly for back and right positions. When the red and green bars are displayed, the cutaway is from the top downwards. The cutaway action is performed by moving the slider. At the bottommost position of the slider, the view is normal LiveView. As the slider is advanced upwards, a plane moves across the model deleting everything behind it. This makes it real apparent that everything in the model is simply sheets of texture, as a cutaway of a wall displays the two sides. Cutaways work in tandem with ClearView modes of all kinds.
VI.
Video Adjustments -
As described in the Textures and Colors article, The brightness, contrast and intensity (amount of shading) can be controlled with the lighting icon dialog. It also controls the direction of the sun for shadow-creating reasons. There is no sunlight shading, because that would preclude realtime rendering; even the shadows can only be seen on stills when requested. There is a separate icon to control turning on shadows for a particular scene.
VII.
Selecting in LiveView - In version 7.0 and above, there is a small arrow icon in the lower right of the LiveView window. This icon can be used to select items in LiveView that can be difficult to select on that plan due to overlapping by other objects. Just click on the arrow, then click on the object, and the whole object will be selected in the plan. No way to do point or edge selection, I'm afraid.
VIII.
How LiveView Works - When LiveView is invoked, the first thing it does is steal the CPU and build a catalog of all the surfaces that make up the total model. This is a time consuming process that increases in length with the number of surfaces in the model, and the source of many complaints about Punch!. However, what has happened is that all the position processing that can be done before the location of the viewpoint is known is done, and doesn't have to be redone until more objects are added. When animating LiveView (that is, when the man is "walking" or the helicopter rotor "spinning", the system is animating the screen by drawing a version of LiveView as fast as it can in the background and slapping the image onto the screen, then starting on the next rendering with the viewpoint position and direction changed. Whether this runs smoothly or jerkily depends on several things: the speed of replacing the rendering image (graphics speed), the "quality" of the image in terms of resolution, and, of course, the speed of the CPU. This is one application where raw CPU speed is a big determiner of performance.
One other thing is done to enhance rendering speed, connected with the speed slider at the bottom of the LiveView window. There are several steps to rendering a scene, such as stretching the texture over the surfaces (plain color is much faster), shading the texture and color, rendering lighting effects, and cutting the grass out of the exterior wallsets. The speed slider makes decisions about what of these steps gets done and which don't. For example, with the slider in its fastest position, almost anything that takes extra time is jettisoned - a gray color is used in place of textures, no shading or lighting effects are done, the grass is not cut. That makes rendering run quite fast. As the slider is advanced, the time-consuming tasks are added back into the mix, until at the slowest position a complete rendering is done at every step. However, regardless of where the slider is set, when the movement stops, LiveView does one final full-up rendering to make the final scene complete. The fact that this last rendering is incomplete (like, grass remaining in the basement) is classic evidence that the video accelerations are interfering with LiveView.
In versions 7.0 and above, I have noticed that every once in a while while running LiveView the entire screen goes blank. I suspect that this is the result of an attempt to break down the LiveView processing further by localizing the viewpoint, and therefore making the animation run faster. When it wanders farther than originally computed for, a new localization has to be computed. Why this must involve blanking the screen (particularly the Plans screen, which must also be redrawn) I don't know. Another mystery is why another preparation has to be done when simply changing floors.
IX.
Turning Off Objects for Speed - In version 4.5 and after, there is a row of icons down the right side of the LiveView window; in version 7.0 and above, the icons are hidden behind a single pencil icon in the top row. These icons will hide certain rendered features in LiveView, in an effort to make animation run faster still. When these icons are clicked, each one disables one class of object rendered, and it shows the same icon with the red circle/slash over it to indicate that that feature is hidden. The features that can be disabled are:
- doors - panelled doors have a modicum of surfaces.
- 3D objects - the most effective of thew lot. Many 3D objects contain many surfaces, particularly curved surfaces and most particularly doubly-curved surfaces, which may be drawn from thousands of facets.
- plants - plants have a single surface, but "texturing" and animating them involves a fair amount of computing time.
- roofs
- texture - texture draping is quite expensive computationally. It is much faster to simply color.
- terrain - complicated terrain can generate tens of thousands of surfaces.
- sky - the sky is animated! (Sorry, Chicken Little). It is animated by *not* moving as it passes by.
- electrical - These and the next two categories) are all 3D objects as well.
- plumbing
- HVAC
X.
Other GUI Widgets - A couple of other miscellaneous items: the Field of View slider gives some control over the angle of view of the viewpoint. Over the range it covers, it pretty much serves simply to magnify the image by about a factor of two.
Also in the lower edge of the LiveView screen is an square array of triangular buttons. These used to be Punch!'s answer to drawing an elevation; however, all they do is set the direction and location of a view from the four cardinal diirections. The projections are perspective.
XI.
New in Version 10.0 - Several new things were added to LiveView in version 10.0 Punch!:
- Palettes - Palettes were added to the LiveView window, with the colored squares icon at the upper rifgt corner. Turning on palettes uses up space on the right side of the LiveView Window, and displays fifteen groups of ten spaces each. Each of these spaces can be occupied by a color or a texture, or even a tinted color (collectively known as a finish), and is loaded simply by dragging the finish to the space and dropping it there. Then the finish in the palette item can in turn be dragged onto a surface on the model and used to color that surface. The fifteen groups each have a name that can be set, so you can collect finishes used in a set of rooms, for instance.
Beyond being just a storage place for used colors, the palette performs another function. If a new finish is dragged onto a palette place that is already in use, then the change is reflected not just in the palette but in all the places that palette finish was used. This is very powerful feature used in playing "what if" with the model. - Dropper Tool - a dropper tool has been added with the dropper icon at the lower right corner. The dropper, when selected, can be clicked on any surface in the LiveView scene, and the color or texture thus selected will be displayed as the top item of the properties menu.
- 3D point capture - The eye icon can be pressed to save the viewpoint coordinates the LiveView is currently using. These coordinates can be exported in a separate file and used with other models.
