Cinema 4D / BodyPaint 3D Program Documentation Tutorials Mechanical Modeling Tutorial Subdivision Surfaces Modeling A Working Example of Subdivision Surfaces Modeling
Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D

The Chair’s Pedestal

Click on the following link to open the scene file for this tutorial:

We will now create the chair’s pedestal using the geometry of the chair’s shell. First we will create a Spline curve to ensure an exact cross-section. Create a Circle Primitive and place it directly below the shell on the XZ plane. Scale the Spline to an appropriate size (see image below). Subsequent steps in the creation of the pedestal will be made easier by scaling it to fit within the polygon row.

Projecting the Spline

Since we will be projecting the Spline onto the surface of the chair’s shell you should leave a slight gap between the Spline and the shell. Also, increase the number of points along the Spline for more accuracy. To do so, select the Spline and select the Current State to Object command from the Mesh menu. This will automatically create a new Spline object and convert the original Spline’s intermediate points to real points. The original Spline can be deleted.

Switch to the bottom viewport and select the Project command (Mesh | Spline). Make sure the Mode is set to View and click on the Apply button. The circle should now lie on the bottom surface of the chair’s shell.

Activating point snapping

In Polygons mode, select the polygons on the bottom of the shell onto which the circle was projected. If you followed all previous steps exactly, your selection will consist of two polygons, as shown in the image below. Scale these surfaces down slightly using the Extrude Inner tool and switch to Points mode. Activate the Move tool and enable its snapping to function. Drag each point that was created using the Extrude Inner tool into position on the Spline, as illustrated at the right of the image below. Make sure the points are distributed evenly along the circle to ensure a smooth transition to the shell. When you have finished positioning the points make sure you disable the Move tool’s snapping function.

Use the Extrude Inner tool to reduce the size of these surfaces and switch to the Use Point mode. Enable Snapping and its Spline Snap option. This was discussed previously in the section about adjusting the sphere Primitive. Drag the points that are created successivelyby the Extrude Inner tool into position on the projected Spline until they snap into place. At the right of the image above you can see what the result can look like. It is important to arrange the points as evenly as possible on the circle so the Subdivision Surfaces object can calculate an even curve and a soft transition to the chair’s basic shape. When done, don’t forget to disable snapping again. This can be done quickly using the P hotkey, which will open the Snap context menu.

Extruding the base

The polygons can be extruded and scaled multiple times (in Polygons mode) to create the chair’s base. Make sure the Subdivision value is set to 0 and the Create Caps option is disabled when extruding. First, extrude the surfaces slightly, as shown in the image below. Click on the New Transform button to extrude the surfaces again, this time until the surfaces stretch to the bottom of the base. Use the image below as a reference. Use the Scale tool to scale the bottom of the base, as illustrated below.

To make sure the bottom edge is less sharp we will add another extrude. We will create the base’s funnel shape by adding a cutline at the mid point using the tool. Select the Knife tool and define a cutline using Loop mode. Disable all other Knife tool options. After defining the cut line, switch to Edgesmode and scale the cut line to shape your base.

The bottom part of the pedestal can be further refined using the Extrude Inner tool’s New Transform function, whose Offset should be increased so it reaches the bottom of the foot. Then apply the Scale tool to scale the bottom of the foot. What the result can look like is shown at the right of the image above. To prevent the edges of the foot from being too sharp, add a slight extrusion, as shown at the left of the image below. The funnel shape of the base can be created using a cut at its center. To do so, use the Loop/Path Cut too in Loop mode. In this mode, a cut will automatically be calcuated around the base in the direction in which the polygons flow.

Our designer chair is now complete. What the image looks like as a fully rendered image, including Global Illumination and a physical Sky illumination, is also shown in the image below.

Click on the following link to open the scene file containing the textured chair:

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