Modeling a wine glass with LightWave
Model creation tools -- Lathe!..

by Tony Gilchrist

(Editor's note: This is the first in a series of LightWave tutorials geared to entry-level LightWave users. Rudimentary LightWave skills are recommended to work with this tutorial. Author/animator Tony Gilchrist has been gracious in sharing some of his tutorials with the DigitalProducer.com community.)

One of the oldest tools to aid in modeling more involved shapes is the "Lathe" tool. We'll use the lathe in Lightwave to build a wineglass (almost as "classic" of a item as the teapot or bouncing ball). First, familiarize yourself with the use of the lathe tool by creating a shape or three with it:

  1. Create a shape.

In Modeler, we can lathe with either a polygon or a curve. Thus both of the shapes are valid for creating a lathe object:
  • Drawing your shape:

The (blocky polygon) shape on the right was created by choosing the "Object / Pen" tool. It is operated by left clicking to create each point.

The (smooth spline) shape on the left was created using the "Objects / Sketch" tool. It is operated by dragging your left mouse button.
  • Editing your shape:

Once you have created the shape you plan to lathe (using either method above), you can adjust the shape by dragging the points around individually with the "drag" tool -- found in "Modify / Drag" (Ctrl - T).

Note: If you wanted to create more accurate curves, or make a closed curve, they can be made more "manually" by using the "Object / Points" tool, and then choosing "Objects / Make Pol, Open Curve, Closed Curve". This would be my preferred method.

  1. Apply the lathe.
  • Activate the lathe tool ("Multiply / Lathe")
  • Click and drag with your left mouse button to define the axis direction of the lathe. (see the diagram below).
  • Don't like the results? Press 'u" to undo, and immediately try again. Repeat as needed.

  • Once you release the mouse button, you can drag the whole lathe axis around by left clicking on it.
  • Want some finer control over the shape of the lathe, the number of steps, and so on? Press "n" to open the numeric requester.

 

The numeric controls for the lathe tool allow you to adjust several values, including obvious things like the number of sides, axis (which overrides any angle you may have drawn), and the Start & End values (which determines whether the lathe is 360 degrees, or less). The three center values control where the lathe center is placed (overriding the positioning data you "drew" previously.

Less obvious is the "offset" value (the last entry in the "lathe" panel). Setting an offset value will cause the geometry to be progressively pushed up along the lathe axis. The simple "corkscrew" shape shown below resulted from latheing only the polygon (shown above) which had a width of 2 or 3 meters, with the settings shown n the numeric panel, which included an offset of 10 meters. Note that using Start and End angles which are more than 360 degrees apart will result in a mess, unless an offset value is also used.

 
  • Note the green lines overlayed on the finished image -- these show the path and direction of the lathe Modification. When you are done drawing and adjusting the lathe, press <spacebar> to stop editing it.

Hint: Avoid Right clicking while using this tool! If you right click, a new lathe will be created, multiplying your geometry without adding any visible detail.

Wine with that?

One of the classic projects for new artists is the creation of a wine glass.

  1. If you still have Modeler open, choose "File / Close All Objects". Then press "a" to reset the viewports (since no objects are present to fit into the views, "a" functions as a view port reset).
  2. We want our wine glass to be approximately the size of a normal wine glass, so just zoom in a bit until we have a grid size of about 20mm. (Why? Since each view-port shows on the order of 10 to 15 rows of the grid, a grid size of 20mm means that the total height of each view-port will be about 20 cm -- or a bit higher that the average wine glass).
  3. Draw a shape very similar to the one shown here. Note that there are only 10 points in this shape. The more points there are in our basic shape, the more there will be in our finished lathe shape, and thus the higher our face count will be. Of course if we wanted a more "bowl" like shape for our stemware, we'd need another point or two to round the top part of the shape.

Again, you could create this using either the "sketch" tool, or by drawing the points one at a time, and connecting them up with "open curve". I built this the second way:

  • Activate the "Points" tool. Using your Right mouse button, run along clicking where you want each point to land.
  • Click "open Curve".
  • Hint: The "Open Curve" tool creates the curve by joining the points in the order of their creation (well, in the order they were selected in, but newly created points are automatically selected). You will need to create the points "in order" -- that is start at one end of the outline curve, and work your way along it). The image below shows the progression of points being added (read the diagram from left to right).

 
  1. Apply the Lathe. If you look at the example, I've set it up so that both the first and last points on the line are resting on the same vertical grid line. When I applied my lathe, I clicked on the black line just above the last point, and then drug my mouse straight down. These steps ensure that there will be no "hole" in core of the resulting object.

    2. Hint: Since I built the curve from the bottom up, but performed the lathe by dragging from the top down, the polygons are all facing the wrong way. In Lightwave Modeler, flipping polygons is a one-key function. Press "f", or choose "Polygon / Flip" in the menu if your polygons are facing the right way. Of course I could have avoided this whole problem by creating drawing from the bottom up to create the lathe.

    Note: Remember, as long as you don't choose a new tool or press space bar, the blue / green lathe axis will still be visible, and the lathe will still be editable. Once you hit spacebar or other wise deactivate the lathe tool, the changes will be committed.

  2. When I saw how ugly my wineglass was, I pressed "undo" to get back to the original curve, and then drug the points in the original curve around (using "Modify / Drag" -- "Ctrl-T"). It is also possible to add points to an existing curve, or remove them -- or if you like, delete the whole curve, and build a new one. Either way, get something similar to the shape shown below -- this time when I lathed it, I drug my lathe axis from the bottom up, and so did not have to flip the polygons. (Before some asks, -- where I'm from we always drink wine from martini glasses).
  3. Next, make sure no points or polygons are selected*, and press "q". The requester shown here should appear. Enter a new surface name, such as "Wine_Glass_Main". We'll apply surface settings to our wine glass shortly.

    4. *When no points or polygons are selected in modeler, the software acts as if everything in the current layer were selected. Thus by deselecting everything we will get the same result as if we selected everything. Strange, but a time saver.

    Note: (you can also "Set Initial Color" in this panel -- which I've done in the image shown here -- this is not necessary, but it does allow you to set a color, and control certain other values).

  4. If you haven't saved lately, what are you waiting for? I'm using a working file name of "wineglass_00". You can find the various saves I made while doing this in the shared folder "I:\tonyg\assign\ week8\wineglass".. The latest version of mine is the one with the highest number -- "wineglass_02.lwo" as of this writing.
  5. I then adjusted the elevation of the whole glass so that the bottom edge of the cup's base was pretty much exactly on the "0" line of the "y" axis. Note in this close-up shot how a large thick black line runs through the space just below the wineglass -- that is the center of the world -- keeping an eye on it helps us to organize and control our objects more exactly.

    A Place to Rest Your Cup…

 c. tonyg 2000