Icosahedron Surface Icosahedron Surface icon

Icosahedron Surface figure

Icosahedron Surface creates a surface representing a linear interpolation between an icosahedron and a sphere. The surface is for comparison to virus particles with icosahedral symmetry; it can be colored by density data for such structures with Surface Color. Icosahedron Surface information is saved in sessions. See also: shape icosahedron, hkcage, meshmol, Cage Builder

There are several ways to start Icosahedron Surface, a tool in the Higher-Order Structure category.

Clicking Show creates the surface according to the settings:

Only one “icosahedral” surface can be present at a time. Changing any parameter automatically updates the surface. Remove closes this surface model, while Close dismisses the Icosahedron Surface dialog. Help opens this manual page in a browser window.

TECHNICAL NOTES

Rounded edges. Even when the Sphere factor is zero, the edges of the icosahedron may appear to be rounded because of the way the model is lit. This is especially noticable in the solid style. Each surface vertex has a normal vector that determines how light reflects off the surface. The vertices at the edges between faces of the icosahedron have a normal vector midway between the normals of the faces. This causes the edges to appear rounded instead of sharp. A higher Subdivision factor (e.g., 32 or 64) will make the edges look sharper.

Coloring. The Surface Color tool assigns each surface vertex a color; between vertices, the colors are interpolated. More detailed color variations will be apparent with a higher Subdivision factor.


UCSF Computer Graphics Laboratory / July 2013