VScad3 Geometric Entities
2.4.5 Surface mode continued.
"Geometry..." continued :
"Polar" : The "Polar Surface" dialog allows a polar surface mesh to be created. A polar surface is basically a polar grid of angle-radius points with a Z height at each point (vertex).
The "Polar Angle" field specifies the minimum and maximum polar angle of the surface (in degrees counter-clockwise). The "Angle Steps" setting determines how many vertex points (radials) will be used along the arcs. The higher the number, the smoother the arcs (and the denser the surface).
The "Polar Radius" field specifies the minimum and maximum radius values for the surface. The "Radius Steps" setting determines how many vertex points (arcs) will be used along the radials.
The "Z Position" field specifies the Z coordinates for each vertex. The number of Z Positions must be equal to the number of Angle Steps times the number of Radius Steps (there must be exactly one Z value for each vertex). To generate Z position values automatically for a flat surface, set the "Z Plane" value and click on "Generate". The "Angle Steps" and "Radius Steps" must be set greater than 1 for the Z Position "Generate" button to function. The Z Positions can also be loaded from a simple ASCII ".dat" file containing one column of numbers. Use the Z Position "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 coordinate where the center of the polar surface should be placed within the model. The Z coordinates are determined by the values entered in the "Z Position" field.
- The "Import Data" button can be used to load a VS3D relief surface (".vs3") file. When loaded, all fields in the Rectangular Surface dialog are set accordingly. In most cases, however, it may be useful to manually set the min/max Polar Angle and min/max Polar Radius to the desired values after importing data. This can be useful for "warping" a sculpted surface onto an arc.
- Click on "Ok" to create the surface with the chosen settings.