VScad3 Geometric Entities
2.4.5 Surface mode continued.
"Geometry..." continued :
"Spherical" : The "Spherical Surface" dialog allows a spherical surface mesh to be created. A spherical surface is basically a longitude-latitude grid with a varying radius at each point (vertex).
The "Longitude Angle" field specifies the minimum and maximum longitude angle of the surface (in degrees from -180 to 180). The "Longitude Steps" setting determines how many vertex points will be used along the equator. The higher the number, the smoother the sphere (and the denser the surface).
The "Latitude Angle" field specifies the minimum and maximum latitude angle of the surface (in degrees from -90 to 90). The "Latitude Steps" setting determines how many vertex points will be used along the meridian. The higher the number, the smoother the sphere (and the denser the surface).
The "Spherical Radius" field specifies the radius value for each vertex. The number of radius points must be equal to the number of Longitude Steps times the number of Latitude Steps (there must be exactly one radius value for each vertex). To generate radius values automatically for a constant-radius (smooth) sphere, set the "Radius" value and click on "Generate". The "Longitude Steps" and "Latitude Steps" must be set greater than 1 (and the radius must be greater than 0) for the Spherical Radius "Generate" button to function. The radius values can also be loaded from a simple ASCII ".dat" file containing one column of numbers. Use the Spherical Radius "Load From File..." button to load such a file.
In the "Vertex Color(s)" field, enter the vertex colors as RGB (red, green, blue intensities - one color per line). Minimum intensity is 0 and maximum intensity is 255. If there are more vertices than colors, then the color sequence is repeated as needed. If only one color is specified, then the entire surface will be that color. The Vertex Colors "Load From File..." button allows a simple ASCII ".dat" file containing 3 columns of R,G,B (Red, Green, Blue) values to be loaded and used as the colors.
- The "Center" field specifies the X,Y,Z coordinate where the center of the spherical surface should be placed within the model.
- The "Import Data" button can be used to load a VS3D relief surface (".vs3") file. When loaded, all fields in the Cylindrical Surface dialog are set accordingly.
- Click on "Ok" to create the surface with the chosen settings.