Twist Tutorial

How do we make a column that is twisted? Not twisted as in a sick and demented way, unless you want that sort of thing, but in a manner that spirals around as it goes up. Well, in the tutorial that is given below, we’ll be making a small column about half a meter tall and about 10 cm in diameter with a 180° twist from top to bottom.

First we start with a shape. Any shape will do, though I really wouldn’t recommend a circle. To make things simple at first, I would recommend a shape that is symmetrical in shape. It will be much easier to see what is going on with the column while you build it. A simple shape, like the one above, with some bits indented or bulging out will make for a more interesting object, though a square, rectangle or triangle will work as well for a first attempt.

The second thing we want to figure out after we have determined the basic shape of our column is how tall we want our column. As I stated earlier I intend to make this column only half a meter (50cm) tall . I’m using the metric system in this tutorial, simply because it makes the math so much easier. Also we know that the column will only twist 180°. So next we need to figure out the degree of rotation we will give each level we extrude.

I’ve discovered that the degree of rotation that seems to work best is 30°. Smaller degrees of rotation create large amounts of patches in your models that are unnecessary and higher degrees of rotation tend to create odd bulges in your column. Though depending upon what you are trying to achieve, the bulges in your column may be a desired effect.

Anyhow, on to the math. The column at 50cm and 180° of rotation at 30° intervals means that we will require 6 rotations at a height increment of 8.33cm per extrusion. Confused at how I got that result? 6 rotations comes from that fact that 180 divided by 30 comes to 6. We get the height of increments by dividing 6 into 50. The result actually gives us 8.333333... into infinity, so we cut it down to 8.33 to make it easier to use.

No need to write the numbers down, I’ll be providing the numbers you need as we go along. Although, if you are doing something different than the numbers I am going to use, I’d suggest getting a calculator and scrap of paper to do your own calculations if you want to keep your column uniform. If you’d prefer to make a more free-form column then be damned with those infernal mathematics.

Okay, now on to the actual modeling portion of the program. We should already have the shape of our column, if not, go ahead and make one now. Make certain that you are making it from the top view and that all the control points of the shape of the column are at a Y coordinate of zero.

When you are happy with the shape you have, go to a front view and select all of the control points of your column shape. Once you have done that, hit the extrude button. The new extruded bit of your column should now be selected instead of the original portion of your column. It also should be a bit lower than the original portion of your column. Lower? Wait a minute, we wanted a column that went up didn’t we? That is easy to fix. While the newer lower portion of your column is still selected, go to your properties panel and select the ‘Selected CP’ tab. Find the data field for the ‘Y’ position, delete the numbers that are there and type in 8.33cm, since that is the height we want this particular increment of the column to be. Hit the return key to get Animation:Master to accept the new coordinate.

If you accidentally deselected the newly extruded portion of your column before you changed the height, this is easy to fix. Just select any spline that makes up the new portion of your column and hit the ‘,’ (comma) key on your keyboard. This should select the whole spline that makes up the new portion of your column again. Then go ahead and adjust the height as described above. Don’t worry the rest of us will wait while you do this.

Once you’ve adjusted the height, select the ‘Group’ tab on the properties panel. Find the column labeled ‘Rotate’ and find the data field for the Y coordinate. It’s not marked as such, but the Y coordinate data field is the middle one on the ‘Rotate’ column. Type in 30 for the amount of degrees we want the new portion to twist. And hit the return key to accept it. You now should have something that somewhat resembles the picture below.

If you would prefer a column that twists in a counter-clockwise direction, just type in a negative value for your degree of rotation.

Now make certain the topmost portion of your column is selected and extrude again. Adjust the height to 16.66cm and rotate 30°. Then another extrude and rotate at a height of 25cm.

Now, those of you following along with a calculator will notice that 16.66 + 8.33 actually comes to 24.99, not 25 as I instructed you to put in. That is okay. Most people will not notice the .01cm (.1mm) difference in the height. Also 24.99 is technically 25 according to some law of mathematics I don’t really remember.that well. Also, it’s easier on the math.

Anyway, since we have stopped at this point, let’s do a quick render of what we have in a bird’s eye view. Again, it should somewhat look like the picture below.

Now let’s continue on with the rest of the column.

Select the topmost spline using the comma key method explained earlier. Do another extrude and 30° rotate at a height of 33.33cm. Another extrude and rotate at 41.66, with the final one done at a height of 50cm. We should now have our completed column like the one seen below.

This technique can be used to create a variety of different things, depending upon what you twist and how you twist it. A couple of different examples are shown below.

The first one is the column I just did here in the tutorial. The second column is actually the Arial Black letter ‘E’ brought in through the Font tool. The last one is actually four different shapes twisting around each other. (Textures on first and second column are from www.Eggprops.com.)

This last type of twisting column making may be the most useful. A ring of circle shapes would extrude into a very nice looking steel cable. Two circle shapes twisted and extruded correctly would make a nice corkscrew or spring once you removed one of the two extruded circle columns when you finished extruding to the height you desire. It is also easy to make a wire mesh in this manner by having two different groups extruded so that one group twists clockwise and the other twists counter-clockwise. This is the technique used to make the wire wastebasket seen below.

I’m sure many more of you can come up with more creative and interesting ways to use this technique and look forward to seeing the results.

I hope some of you have found this tutorial helpful. If you have any questions or need clarification on anything, do not hesitate to ask. E-mail me at HeadlessBill@email.com.