www.schorsch.com

# Rayfront 1.0 User Manual

## Generators

The following programs are included with friendly permission by it's author Paul Bourke.

Those programs let you create elaborate geometry objects with a single command, in case you desire to write your geometry data manually.

### Triangulate

```  triangulate mat name xyzfile xcells ycells [zscale]

where:
mat      the material name for the surface
name     the base name for the surface elements
xyzfile  the file of spot heights arranged as x y z values
xcells   the resolution of the gridded mesh in the x direction
ycells   the resolution of the gridded mesh in the y direction
zscale   height scaling ```

The triangulate program takes a data file "xyzfile" containing a set of 3D points and generates a gridded triangle mesh over those points. The data file is a text file and contains one point per line, describing the X, Y, and Z coordinate of that point in white space seperated format:

```12.3438 2300.38 1
506.095 1399.25 1
1199.81 72.5907 1
5406.57 20000 1
5246.1 19364.2 1
5088.1 18743.4 1
5016.51 18315.4 1
4806.67 17499.4 1
...```

### Gensuperellipse

` gensuperellipse material name eps1 eps2 ribs slices`

Generate a Radiance desciption of a superellipsoid. Two parameters (eps1,eps2) control the curvature of the ellipse. Special values of these parameters are

```    -> 0       square
< 1   cuboid
1       spherical, ellipsoid
2   octahedron
> 2       pinched```

There is a smooth transition of forms between these values These objects are created from polygons, ribs and slices governs the number of polygons horizontally and vertically that are used to create the form. Typical values are 16 ribs and 16 slices. The superellipsoid is centered at the origin and of unit size.

Mathematics

The superellipsoid is defined as all the points lying on the surface.

```                    +-                               -+
| cos(theta)^eps1 * cos(phi)^eps2 |
X(theta,phi) =  | cos(theta)^eps1 * sin(phi)^eps2 |
~               | sin(theta)^eps1                 |
+-                               -+```

### Architectural Generators

The following generators create a variety of architectural elements. It is recommended to experiment with the parameters for best results.

```   genarch material name r dy xstart n

gencolumn mat name height (s,c) r1 r2 overlap num

genlinearstairs mat name dx dy dz nsteps stepthickness
[-r (l,r,b) railheight railposts railthickness]

genspiralstairs mat name radius height thetamax nsteps stepthickness
[-r railheight railposts railthickness]

genvault material name dx dy dz n extx exty```