Create Animated Sweep NURBS with MAXON Cinema 4D

Open a new project in Cinema 4D and set a render camera. While you have a choice of cameras to use, the Target Camera is easiest to use for this project. Select the target camera from the Standard toolbar, or from the file pulldown menu; select OBJECTS-> SCENE-> TARGET CAMERA.

The camera should be set facing along the Z-axis, with the following
coordinates (fig. 1, near right), with the target’s coordinates further
down the Z-axis (fig. 2, far right):

The short focal length and wider aperture width will force the
perspective of the shapes that will be generated by the sweep NURBS
object.

Last, change the camera view in the viewport to your newly created camera by selecting "CAMERAS-> SCENE CAMERA->(your new camera)." Your new camera will show up by name. By default, Cinema 4D has named the new camera: "CAMERA." Double click the object to rename it.

While placed under the Sweep NURBS object as children, the sweep object
creates geometry by using two or three spline shapes. We’ll use two
here. The first shape is the profile of the object, known as the "CONTOUR."
The second spline is the "path." This is the direction the contour will
travel to create the object’s shape. I will create the first spline by
selecting a star shape from the standard tool bar. In the star’s
attribute window (select Object), you can determine the characteristics of the contour, including the number of points in your star object. Select 5 points.

Next, you need to draw a path for this star shape to travel along. Press F2, or select " Top View" from the viewport "VIEW"
pulldown menu. From the standard tool menu, select the b-spline tool
and draw a path along the Z-axis, starting at a point beyond (0,0,0)
and continuing toward the camera. This will not only create a path, but
also set a direction for the path. ( Note: The beginning of the
path is indicated by yellow, while the end of the path is indicated by
a dark orange color.) If you’ve drawn this backwards, select "STRUCTURE-> EDIT ->SPLINE-> REVERSE SEQUENCE" from the file pulldown menu.

With the path spline still selected, you may want to edit the points
along the spline so they don’t all lie at (0) on the Y-axis. Select
another view using F1, F3, F4 orF5, then, using the move tool, select
and move the individual points.

With the spline still selected, hold the option key down and select the
Sweep NURBS object from the Standard tool bar. This should place the
spline under the Sweep NURBS object as a child. This hierarchy is
visible by opening the Object Manager (Shift-F1). Next, attach the star
object as a child by dragging its name or icon on to the name (or icon)
of the Sweep NURBS object in the object manager.

Changing the attributes of the Sweep NURBS object is really very easy.
As with other objects in the MAXON interface, the Attribute manager for
the object appears, by default, when the item is selected in the Object
Manager. Among the various object controls for this NURBS form is "GROWTH."
This parameter moves the extrusion of the contour along the path (and
optionally through the a third spline, known as the "rail" spline). A
value of 0% means that it’s at the beginning of the path spline (yellow
part); at 100%, the contour is "swept" to the full length of the path.

If you decide to animate this feature, you can set keyframes for that
attribute by control-clicking on the empty circle next to the name of
the characteristic.

In the section that determins Caps and Rounding, you can change the
end’s cap (facing the end of the path) to Fillet Cap in order to create
a more interesting shape. The amount of steps determines the level of
subdivisions. The radius will determine the distance of the fillet from
the original contour shape.

You can add a new material by accessing the Materials Manager (Shift-F2) and selecting "NEW MATERIAL" from the file pulldown menu (cmd-N). Duplicate this material by holding
down the control key and then click and drag on the existing material.
(Note: This duplication method works for objects in the ObjectManager
as well.) With the duplicate selected, find the material’s attribute
window, under the "BASIC" settings, and turn on "LUMINANCE"
by clicking in the check box next to its name. Drag the first material
onto the icon for the Sweep NURBS. Do the same with this luminous color.

With the white texture tag selected for the luminous material, type
"C2" into the Selection option found within the tag’s Attribute window.
"C2" refers to the second caps portion of the object. "C1" would refer
to the first (unseen) cap. Our rounding is selected by inputting "R2."

A quick render of this scene (Ctrl-R) shows the luminous texture
applied to only the face, with the normal texture applied to the rest
or the object. Here’s the frame-by-frame version of the final effect.
Check it out on MAXON’s Web site, and have fun creating your own.

Ko Maruyama
Freelance Animator
Los Angeles, CA

In addition to his contract animation work in Hollywood, Ko is a Pixel
Corps senior artisan on the Particl Effects Team and teaches at the Art
Center School of Design in Pasadena.

You can create animated sweep NURBS objects with two or three spline
shapes. While we won’t employ one here, you could use a third spline to
govern the scale of the contour as it travels along the path. This
third spline is known as the "rail."