Intro To 3D Modelling, Lesson 3: Viewports And Construction Planes

This week we’ve been learning 3D modelling with Rhino 3D and have spent the first two days getting acquainted with the software. Today we’re taking a look at viewports and construction planes.

Halfway point! Congratulations on making it to day three. Let’s keep truckin’ and learn about viewports and construction planes. These two elements help us further understand what we are looking at, the units we are working in and how they affect our geometry.

Viewports

When working in Photoshop or MS Paint, the photo or illustration you are creating is visible from one available view. The front. This makes sense because it is a two-dimensional image. In 3D software, you need to be able to see what you are doing from any number of views, as you can manipulate the image from any angle.

For our purposes, there are two types of viewports: elevation (top, right, front) and perspective.

Looking through an elevation viewport is like looking at a drafted drawing of whatever your model is. The view type is called “projection” or “parallel”. Perspective is not displayed so that you can see how everything lines up. Using the perspective viewport is a much more familiar setting, like looking through a normal camera that you can orbit around and see your object from all sides.

By default, your viewports, or those four rectangular windows, that open on your screen are set to (going from top left, clockwise) Top, Perspective, Right and Front. This is a standard setup in most 3D programs. If you want to add more viewports, you can click and hold on the viewport window tool on the top tool bar and this will come up (see image to the right).

You can then customise your layout of viewports to your heart’s content. The top left button is what you’ll see by default. If you ever need to reset these, just click that one and your viewports will reset to the original configuration.

If you click and drag on a viewport name in the upper left hand corner of the viewport window, you can drag the viewport around. Likewise, you can click and drag on the seam between windows and resize to your needs.

By right-clicking on the name of the viewport, you get immediate access to a really awesome sub-menu (see image to the right).

With this menu, you can change the display from wireframe to shaded preview. You can change lens length, save views, insert background images, and really customise every viewport to your needs. You can even turn off “Parallel” view and change it to perspective if you need a more dynamic view of your model from one of its side views.

Now that we understand the viewports are looking through, let’s take a look at what is through the viewports.

Construction Planes

This is the easiest way that I can describe construction planes: When you are building with LEGO at your dining room table, your table is your construction plane. It is the plane which everything is being built upon.

From the Rhinoceros help page:

The construction plane is infinite. The array of lines lying on a specified portion of the construction plane in the viewport is the grid. The grid is a visual reference only.

Construction planes are what plane you are building your model from. These grids show you both where in space you are working and the size at which you are working. When you create a new document in Rhino, you can indicate the unt scale of the grid.

The numbers you input are then linked to that scale unless you indicate otherwise. For example, if I set up my document in “inches” and I make a circle with a diameter of “1”, Rhino will create a 1″ diameter circle. Then if I create another circle with a diameter of “2 centimeters” it will create a circle with a diameter of 2 centimeters within the same document because I specified the unit within the comand.

When needing to build from a surface, you can orient the constuction plane from said surface with the “Cplane” command and selecting object from the menu. You can then select an object and build off of that object.

Whatever viewport window you’re working in, the green line on the grid always means “Y” and the red line on the grid always means “X”. Likewise the “Z” axis is always coming at you. The easiest way to remember this is to use the hand gesture (pictured to the right).

These axeshelp you understand where in space you are. By using multiple construction planes you can understand where your model is in space. If you’d like to know more about axes and coordinates, check out the video “0,0,0” on PolyPlane.

Tomorrow we’ll talk about object selection and object transposition. See you then!

This lesson was created by Gabriel Mathews of PolyPlane. You can follow him on Twitter @PolyPlane and on Facebook.