Tutorial 2

How to create a perfect Boing Ball

Boings are easy, once you know how!
Here's a step by step guide to creating a 16x8 (16 side, 8 segment) presentation of the defacto Amiga logo. You can adapt the instructions to create any other presentation you fancy.

You're talking Balls!

The first thing to do is generate a very crude Boing Ball with the desired number of sides and segments. By this, we mean the number of coloured sections making up the 'longitudinal' aspect (sides) and the number of 'slices' or segments from 'north' to 'south'.

You do this by going into Modeler and clicking on the Objects menu, Create/Ball tool. This will provide you with a 'ball-creation' cursor. You can drag out a bounding box using this cursor in the View Windows and thereby create the basis for a ball. But don't! Instead, click on the Numeric button.

This pops up the Ball parameters panel, shown below.

Here, you can set the ball's structural Type, its number of Sides and Segments, its X,Y,Z dimensions (Radii). The default 'Globe' type is the one you need. It's divided 'horizontally' and 'vertically'. Experiment with the tesselated version to see the difference. If you experimented with the ball-creation cursor, the panel will display the values you generated with it. Just press the Reset button to get things back to the defaults.

Now, enter the desired number of Sides (16) and Segments (8) in the appropriate fields. If you prefer the 12x6 Boing format or any other combination, just enter the relevant numbers. Leave the default Center at 0,0,0. That's the centre of LightWave's grid system for both Modeler and Layout, the logical place to put the Object you'll create. You can make the X,Y,Z dimensions (Radii) any size you like, providing they're all the same. It is a perfect ball we want after all! The defaults will be probably be fine. OK the settings to close the panel and get back to the Modeler windows. You'll see the bounding box/cursor has set everything up and awaits your approval. So, click the Make button to complete the construction. The box/cursor will remain on screen along with the generated Ball. Free up the cursor by clicking on one of the the Menu button at the top of the screen. You should now see something like this....

In this graphic, I've activated the 3D view window (top right) with a Static Solid presentation. The object has been rotated on screen with the mouse to give it a classical Boing 'pose'. It often helps to see what you've created in 3D.

At this stage, the ball is pretty angular and faceted. Don't worry about it. The important thing is that it's composed of exactly the right number/shape of polygons (16x8=128). These will eventually be coloured Red and White, in true Boing tradition. If the ball were subdivided into smaller polygons at this early stage, you'd never get the colours right. So, whatever presentation of Boing you want to create, always generate this 'minimal ball' first.

Half a Ball is Better than One!

The next step may seem a bit odd. We're gonna discard half the ball and work with a hemisphere. The reason will soon become apparent if you try to select all the facets you want to be one colour, say Red. Using the three view windows, you'll find it next to impossible to determine which facet (polygon) is selected and which isn't. One hemisphere will obscure the other and you'll be pulling your hair out in no time. So, in the Face or the Left view, select all the polygons in the lower hemisphere so you can cut them out. Do this by first putting the interface into Polygon selection mode. That's the second button from the left at the bottom of the interface. Now with the LMB down, drag the cursor over all the polygons in the lower hemisphere. They'll become highlighted in yellow to indicate they're selected. You'll also see their Normals extending outward. To learn more about Normals, check out Tutorial 1.

If everything's gone to plan, the screen should look like this...

It's worth remembering that if you missed out any polygons after releasing the LMB, you can continue with the selection process with Shift/LMB. If you continue with a straight LMB as before, the selection process is reversed!

OK, let's get rid of these polygons by clicking the Cut button. That's the one a little further along the bottom row. The result is shown below.

NOTE: You could just 'Hide' the lower hemisphere and work on one at a time. This is perfectly OK, but my method provides insight to a couple of Tools you woudn't otherwise need. As in everything LightWave, there are usually several routes to a particular goal.

Reds First

Now we have an uncluttered hemisphere, we can start selecting the facets to be made Red and those to be made White. We'll do the Reds first.

The MOST IMPORTANT thing to remember when selecting is to START AT THE POLE and work down to the EQUATOR! I'll not explain why, but it's important. By all means experiment with the alternatives and you'll soon realise why!

So, select one of the polar triangles using the LMB (Polygon mode of course). The adjacent polygon(s) will also be selected. That's 'cos they share a common side at the position you clicked on. Selection is done via sides. Deselect the unrequired polygon(s) by reclicking them with the LMB at a place away from the poly you actually require. It's easier to do than say. OK, continue selecting alternate polar triangles (Shift/LMB), deselecting (straight LMB) adjacents as you progress, until the required half are selected. All being well, you should see the following...

In this graphic, I've dragged the Top view window to full screen so you can more easily see the required result. Make sure only the alternate triangles are selected or your Boing will Bomb!!

From here on in you'll need all your attention on the selecting routine. You must now look at the first ring of polys outside the polar triangles. Select the first one so it's 'between' two selected triangles. You're creating a checkerboard effect with selected polys. Deselect the adjacent poly as you progress. Use Shift/LMB and straight LMB to control the action. By clicking the most appropriate side of the poly you need, it becomes quite easy to keep things on track.

If things go to plan, the next graphic should match your results.

You'll probably have to stare at this a while to see what's going on. The Normals are the best guide to which polys are selected and which aren't. Indeed you may already be wishing you'd gone for the simpler 12x6! Don't worry, once you get the hang of selecting the right polys, even a 24x12 will be child's play!

The next graphic shows how the next ring of selected polys affects the picture.

And the final 'equatorial' ring.

Imagine what this would look like if the other hemisphere were present with all its Reds selected...impossible!

Call 'em Red

All these selected polys will be Red in the final model, so we must tell LightWave to make 'em so. You do this by clicking on the Polygon menu button in the row across the top of the interface and then on the Surface tool in the Transform group on the left hand side. This pops up the Change Surfaces panel as shown below.

The first thing to do is change the name of the selected surface from 'Default' to something more appropriate. 'Red' sounds good to me, so type in the name on the text field. Using the RGB sliders, you can assign whatever colour you fancy for this surface. I guess (255,0,0) will be about right.

The above graphic comes from LightWave5. Earlier versions may not exhibit the colour swatches as shown here, but the process is more or less the same.

You can leave all the other Surface parameters at their default settings, though it will be useful to activate Smoothing if it's available on your panel. This will automatically invoke Phong shading when we finally get around to rendering the Surface. If Smoothing's not there, don't worry, we'll catch it later.

If you're interested in the Smoothing Angle parameter indicated on the panel, you can learn all about it by popping over to Tutorial 1.

Click the Apply button to fix all these settings for the named Surface (Red). The panel will close and you'll be back at the previous screen with 'Red' selected.

Hidey Ho!

One of Modeler's most useful functions is the Hide system. You can literally hide any part of your object you'd rather not see in the view windows. You can Hide Sel(ected) items or Hide Unsel(ected) items. Afterwards, you can Unhide anything you previously hid away. Great! When something's hidden, you can apply tools to the visible parts without worrying that they'll affect what's hidden. Hidden stuff is safe from the actions you apply on screen. Let's use it to complete the Surface assignments.

Since all the Red polygons are currently selected (and what a job that was!) click the Hide Sel button. It's the first one in the Visibility group of tools at the lower left of the interface. This will result in all the Red polys vanishing from the screen. They haven't been cut, you just can't see them. And when they're hidden you can play around with the remaining stuff as you like. Here's what you get...

Now this looks pretty logical doesn't it? With the Reds hidden, the equatorial ring appears as you would expect, kinda notchy. The rest of the polys are less obvious. There should be 'holes' where all the Reds were and remaining Default polys everywhere else. The easiest way to satisfy yourself that all's well is to select everything on screen. A quick select method is to draw a lasso around the object using the RMB . All visible polygons will become selected. The Normals will confirm the picture. OK?

OK, whether the on-screen stuff is selected or not, it's all gonna be White, right? That's logical enough. Red is hidden so what's left has to be White. So, pop up the Change Surfaces panel (Polygon menu/Surface tool). Name the Surface White, colour it (255,255,255) and activate Smooth if available.

Here's the screen...

Click the Apply button to fix the White Surface parameters. This closes the panel and you're back to the White Polygons. Deselect them if they're selected (yellow). You can do this by going over them all with the LMB, but the quickest way to deselect Polygons (or Points for that matter) is to RMB click the appropriate Mode selection button at the bottom left of the interface.

Just to confirm everything's as it should be, Redraw the Red polys by clicking the Unhide button. You should be back to the crude hemisphere, as follows, with all its facets correctly labelled and colour assigned. You can confirm this by checking the Polygon Stats (Statistics) panel. You get to this via Polygon mode (bottom row) using the Display menu (top right). This menu provides a Stats button in the Selection group (left side).

Click the Stats button to obtain statistical details of the polygons in the current object. The Polygon Statistics panel will confirm we've got 128 in total (16x8). It will tell us how many are three point, four point, etc. It will also confirm that all 128 polys have been assigned a Surface description. You can get details of each Surface's polys by selecting the required name (Red or White) using the scroll bar. You can select any group of polygon types (by their number of Vertices/Points). Make your selections using the 'plus' buttons. You can determine which (if any) polys are non-planar and if necessary plan to correct them. Deselect polygons with the 'minus' buttons.

OK, we've finally got one half of a crude Boing Ball. Let's create the other half. It's real easy!

No, we don't have to repeat all the previous stuff to obtain the bottom half. We simply generate a mirror image and turn it a little, geddit? Here's how.

Mirror, Mirror on the Ball

Since we created the original Ball with its centre located at (0,0,0) our hemisphere is resting nicely on the XZ plane. All its 'equatorial' Points are located there. So if we use the XZ plane as a mirror, we'll get an equal and opposite hemishere, also resting on (and below) the XZ plane.

To do this, you must click on the Multiply menu (top row) and then on the Mirror button (upper left column). The cross-hairs will change to the mirror-creation cursor. A mirror plane may be placed anywhere on the view screens by clicking the cursor at the desired place. However, this can be a bit hit and miss if you wish to position the mirror very accurately (which we do). The best way is to pop up the Mirror panel by clicking on the Numeric button. This provides you with all you need to place the mirror exactly on the XZ plane.

When you first use the Mirror tool, it can be a bit confusing as to which Axis to select to set the mirror's orientation. This isn't helped much by the use of the label 'Plane' for the X,Y and Z axes. However, with only three options available, you'll quickly find it's the Y Plane/axis we need here.

Leave the Position for the Mirror at the default Zero units. This will place it in the XZ plane and coincident with the hemisphere's equator.

The Mirror's 'edge' is identified with yellow markers in the appropriate windows, as shown below.

The lower edge of the hemisphere is coincident with the mirror and in this shot, mutually excluded from the graphic.

So, to create the second hemisphere, click the Make button. An exact mirror image will be drawn

You can cancel the Mirror by clicking one of the Menu buttons (top row). The object now consists of two identical hemispheres, with Red and White surfaces in mirror image positions. That's not what we want of course. The checkerboard effect must 'cross the equator' and is easily achieved by rotating the lower hemisphere by an appropriate amount.

A Bit of Spin

The first thing to do is to select all the polys in the lower hemisphere. Use the LMB to pick them out. Next, we need to Rotate them around the axis of the sphere, that is the Y axis. Click the Modify menu (top row) and then the Rotate tool in the Position group (upper left column).

The rotation must be very accurate, so click the Numeric button to pop up the Rotate parameters panel, shown below.

The required rotation is precisely one facet or 360/16 degrees. That's 22.5 degrees, so enter this value in the Y Angle field. A 12x6 Boing needs 30 degrees, a 24x12 needs 15 degrees, etc. Click OK to make the change. When it's done, the ball should appear exactly as before, though the lower colours (which you can't see of course) have been displaced by one facet.

Weld or Merge Points

OK, you could consider the basic design stage is now over, but it's not quite right. The ball is actually two unattached hemispheres. The Mirror tool creates a mirror image object, but it doesn't do any joining. To fix this we need to 'weld' them together. That means dealing with the Points which define the polys, so it's done in Points selection mode (bottom row).

The 16 Points around the upper 'equator' and the 16 Points around the lower 'equator' actually lie in matching pairs. Each pair occupies the same location in 3D space. If each pair were welded together, then the hemispheres would become a single sphere. You can weld two or more Points into one using the Weld tool, but that would mean selecting one coincident pair at a time and welding them. That's OK if you like the idea. But beware, make sure you don't co-select any Points diametrically opposite the ones you're working on. Weld those as well and the ball will burst!

A far easier method is to invoke the Merge tool (Tools menu/Merge button under the Points group, centre left). This tool will automatically merge/weld together any group of Points occupying the same location. The result is a single Point made from each group. All groups are merged symultaneously and the tool works without pre-selection, according to its inbuilt parameters.

So, run a Merge Points (Automatic) on the object and it'll be right.

As you see below, sixteen of the thirty-two 'equatorial' Points have been eliminated. The thing is now whole.

Phew! All this for a red and white 'ball', if that's what you call it. Not very impressive!
Well, this IS a blow by blow Tutorial and you'd no idea how to even start!
Stay with it, the rest is the fun part!

Save it Now!

That's a heading you'll see quite often in my Tutorials and it means what it says! Get into the Saving habit and avoid a lot of grief! This crude Boing Ball, no matter how primitive it seems, involved a fair amount of work. Why lose it all for the sake of a simple Save...! So, click on the Objects menu/Save As button and get everything onto the drive. You'll be so glad you did!

Call it something descriptive. How about Boing16x8CRUDE.lwo ? It does exactly what it says on the tin!

Shape Up!

From here on, we'll be concentrating on getting the ball into shape. You might run a trial render of Boing16x8CRUDE.lwo to see how things are progressing. At least you can confirm all the Red and White bits are in their proper places. Other than that, the object really doesn't stand much scrutiny. Its polygons are far too large to render really smooth. Check it out below.

So, the first improvement you can make is to sub-divide your polygons into smaller units. Perhaps the surest first step to good renders is to Triple all the Polygons which make up your Object. Tripling creates triangles by sub-dividing any quad-polygons (4-sided) and any higher polys, if present in the mesh. Tripling's not essential, but it is certain. Why? 'Cos 4-sided and higher polys may not be planar (flat) and non-planar polys produce render errors. Triangles are ALWAYS planar. Think about it.

OK, let's Triple all the quad-polys in the crude Boing Ball. There are 96 of 'em, as you may have noted on the Polygon Statistics panel. It's a doddle to do with the Polygon menu/Triple tool. Here's what you get...

By dividing the quads into triangles, the Phong shading routine will always give you good results when you render the object. As I said, it's not always essential, but it is certain. None-the-less, we'll be creating quad-rich objects in other Tutorials which render just great. You pays your money and you takes your choice. It's usually OK, but if you hit niggling render errors, always check out the effect of Tripling your polys.

You may have noticed that the tripling process hasn't really smoothed out the angular appearance of the ball. The large flat facets have simply been divided into triangles. However, what we do have is a completely triangular mesh and that's always good. Let's look at Smoothing next.

Subdivide Smooth

Subdividing requires triangles. That's the way Modeler works. If you attempt to Subdivide quad polys, you'll get an error message telling you to Triple first. Subdivide bisects the angles and edges of triangles. The Subdivide Smooth routine adds a little finesse to the process. It integrates the Smoothing Angle modifier, so you can actually smooth away the angular appearance of the mesh. New Points are inserted at elevations which impart a geometrically and therefore visually smoother surface. You invoke the process in the same manner as the Triple tool. Use the Polygon menu and click on the Subdiv button. This pops up the Subdivide Polygons panel shown below.

Here, you have several options for polygon division. Click the Smooth button to enable the smoothing algorithm. Leave the Max Smoothing Angle at the default value. This aspect is too complex to consider here, but you can learn more about the Maximum Smoothing Angle by popping over to Tutorial 1. There's a comprehensive Tutorial on the Subdivide Smooth process in the WaveGuide Manual.

Here's what the process creates...

Notice how the curvature of the ball has been enhanced by the smoothing process.

I reckon this Boing Ball is just about finished. A further Subdiv/Smooth will make it even better, but will double the poly count and increase render times. By all means try it if you have plenty of RAM and a lot of patience. Whatever, don't forget to save the Object to the drive under an appropriate name. How about Boing16x8PERFECT.lwo.

Here's a quick render to prove it out.

There are lots of improvements you can make to the Object in Layout. Think about making the Boing's surface slightly reflective, so you get a highlight from the lighting. Use a Spotlight to enhance the curvature and check out the Sharp Terminator feature. Think about a.... hang on, that's another Tutorial already!

Above all, enjoy!

As someone once said, 'Perfick'

If you find any errors in this Tutorial please email me and I'll fix them at once.

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