Rounding

Realsoft Graphics Oy		Rounding
	Chapter 3. Subdivision Surfaces

The rounding feature allows you to round edges with a desired rounding radius. Rounding is different from creases in that it can only be applied to edges. The biggest advantage is that the size of the rounding is freely adjustable, whereas creases have only three different values (sharp - semi-sharp - rounded).

Four identical SDS cubes with different edge rounding

Rounding is an edge specific attribute, which can be set in the edge editing and face editing modes. Rounding a face corresponds to rounding all the edges of the face.

1. Create a SDS cube. By default, no rounding values are defined for the edges and the surface looks like a sphere.

SDS cube with no edges rounded

2. Switch to the face editing mode and select the top face. Open the property window and set the 'Edge Sharpness' to 'Free'. This allows us to specify exactly the desired rounding radius. Change the 'Edge Rounding' field in the 'Spec' tab to 0.001 meters. In other words, define 1 mm rounding for all the edges of the top face.

	Note
	You may have to set the number of decimals to a value of 3 in the Preferences Window - Metrics tab to be able to enter the value of 0.001.

The cube now defines the following surface:

Top face with a 0.001 m rounding

Edges of the top and bottom faces rounded

3. Now, select the bottom face and set the rounding of it to 0.001 as well. You now have a cylinder whose both ends are slightly rounded.

4. Switch to the edge editing mode, select two opposite vertical edges and define a 0.001 rounding for them as well.

0.001 rounding defined for two opposite vertical edges

Identical SDS control polygon cubes with different rounding values

It is already easy to guess what happens if you define rounding for all edges: the result is a cube with rounded edges.

A box with rounded edges

Let's create a box with rounded edges.

1. Create a SDS cube.

2. Switch to the face editing mode and select the top face. Subdivide and extrude the top face inwards as shown in the figure below.

Select, subdivide and extrude the top face

Vertical faces subdivided

3. Now, select all the vertical faces (including the inner side faces) and subdivide them. Make sure you set the 'Region' to 'Seperately' in the Subdivide Face tool control bar.

4. Select a face pair in the middle of a cube 'wall' and apply the tunnel tool. This drills a hole through the wall. Repeat this for all four sides of the box.

Walls punched with the tunnel tool

5. Use the drag box to select all faces and set a 0.001 meter rounding radius through the property window. The box is now ready.

Edges with roundings

Model a sink

Let's create a beautiful sink. Similar to those you can find in any modern bathroom.

Example project: 'tutorproject/modeling/sds/sink'

1. Switch to the front view and create a SDS cube representing the sink from the front.

A SDS cube in the front view

One of the faces extruded

2. Enter the face editing mode and extrude the 'back face' of the SDS cube.

3. Use dragging to select all the faces in the extruded part and define a small rounding (e.g. 0.002 meters) through the property window.

0.002 rounding defined for the selected faces

4. Select, subdivide and extrude downwards the remaining 'top' face of the sink as demonstrated by the attached image.

Rightmost top face selected, subdivided and extruded downwards

5. Switch to the edge editing mode and round the four edges shown in the image to value 0.002.

	Note
	It can be difficult to select edges in the shaded mode because the edges are partially hidden by the actual surface. You can switch to wire frame rendering mode to select the edges easily.

Edges marked with red color rounded

Top face subdivided. One of the new faces subdivided and extruded inwards to form a place for soap.

Our sink starts to look like a real sink already. However, all real sinks have some additional details like a place for soap. Use your imagination to further edit the sink. For example, to create a place for a soap by subdividing and extruding.

After some practicing, you will be able to create a real sink in just a couple of minutes.

The finished sink


Creases		Assigning Materials to Faces