R3D_OBJECTS(1)

NAME

rd3_objects - object types used by the Raster3D package

DESCRIPTION
These are the object descriptor types, and the required parameters, recognized by the render program and other components of the Raster3D package.

Object type 1 - triangle
x1, y1, z1, x2, y2, z2, x3, y3, z3, red, green, blue;

Object type 2 - sphere
x, y, z, radius, red, green, blue;

Object type 3 - cylinder with round ends
x1, y1, z1, R1, x2, y2, z2, R2, red, green, blue.
 (R1 is the cylinder radius, R2 is currently ignored).

Object type 4 - not used

Object type 5 - cylinder with flat ends
x1, y1, z1, R1, x2, y2, z2, R2, red, green, blue.
 (R1 is the cylinder radius, R2 is currently ignored).

Object type 6 - plane
x1, y1, z1, x2, y2, z2, x3, y3, z3, red, green, blue;
 The plane is defined by any three points. It's color fades from full intensity in the foreground to half-intensity at the back.

Object type 7 - Vertex normals
Explicit vertex normals for preceding triangle object. This object must directly follow the triangle object, and uses the same format.

Object type 8 - Material properties.
These values override the specification of lighting and specular highlighting in the header records, allowing some objects to have different surface properties from the rest. The specified values will apply to all subsequent objects until an object of type 9 is encountered. The parameters are read as free format floating point numbers from the next line of the input stream:
 8
 MPHONG MSPEC SR SG SB CLRITY OPT1 OPT2 OPT3 OPT4

MPHONG
    value >=0 overrides the global Phong power for specular highlighting

MSPEC
    value >=0 overrides the global specular scattering contribution

SR,SG,SB
    RGB triple specifying color of reflected light (by default all specular highlights are white) A negative value for any component will default to the base colour component of the object being rendered.

CLRITY
    The degree of transparency for this material, with 0.0 indicating an opaque surface and 1.0 a purely transparent one.

OPT1
    Affects processing of transparent objects which belong to the same material, but occlude each other (for instance the front and back surfaces of a transparent molecular surface).
     OPT1 = 0 will render all outward-facing transparent surfaces
     OPT1 = 1 will render only the topmost outward-facing surface
     OPT1 = 2 will render both the outward- and inward- facing surfaces of transparent spheres and cylinders

OPT2
    Selects from several variant treatments of transparency as a function of alpha and the Z component ZN of the surface normal.
     OPT2 = 0 T(ZN) = 0.25(1+cos(pi*alpha*ZN)^2
     OPT2 = 1 T(ZN) = (1-abs(alpha*ZN))^2
     OPT2 = 2 T(ZN) = 1 - alpha ^ (cos(pi/4) / abs(ZN))
     OPT2 = 3 T(ZN) = 1 - alpha Option 0 is an empirical function that I think looks good.

OPT3
    Not used

OPT4
    Non-zero to indicate that additional modifier records follow immediately. Each modifier must constitute a single line, and OPT4 tells how many of these lines there will be. Here is a complete list of modifiers currently available, and their parameters
     SOLID    RED GREEN BLUE
     BACKFACE    RED GREEN BLUE MPHONG MSPEC
     FRONTCLIP    ZFRONT
     BACKCLIP    ZBACK
     BOUNDING_COLOR    RED GREEN BLUE
     BOUNDING_PLANE    BPTYPE X Y Z Xnorm Ynorm Znorm
     ORTEP_LIKE    used to create fancy ellipsoids (see rastep documentation)

Object type 9 - End_material
Terminates application of all previously defined special material properties (object type 8) or isolation from TMAT transformation (object type 15).

Object types 10,11,12 - Label descriptors
These object types are used as label descriptors. The current version of render ignores them unless the -labels option is selected on the command line.

Object type 10 - font_name size alignment
    Legal values subject to details of font processing implementation.
     font_name is any font name recognized by libgd
     size is the font size in points, but is modified by render's -fontscale option
     alignment is "Left", "Right", "Center", or "Offset".

Object type 11 - Label text
     X Y Z R G B (On one line) label position and color
     Label text (On 2nd line)

Object type 13 - Glow light source.
This is a colored, non-shadowing, light source with finite [x y z] coordinates and a limited range of illumination. Control parameters are read in free format from a single line of input following the line specifying the object type.
 13
 GLOWSRC(3) GLOWRAD GLOW GOPT GPHONG GLOWCOL(3)

GLOWSRC(3)
    [x y z] coordinates of light source

GLOWRAD
    limiting radius of light source (see GOPT)

GLOW
    fractional contribution (0.0 - 1.0) of glow light to total lighting model

GOPT
    (integer 0/1/2/3/...) - controls functional form in which limiting radius is applied [under development]

GPHONG
    Phong parameter controlling specular highlights from glow light

GLOWCOL(3)
    RGB triple specifying color of glow light source

Object type 14 - Quadric surface

x, y, z, limiting_radius, red, green, blue, A, B, C, D, E, F, G, H, I, J

Quadric surfaces include spheres, cones, ellipsoids, paraboloids, and hyperboloids. The motivation for this code was to allow rendering thermal ellipsoids for atoms, so the other shapes have not been extensively tested. A quadric surface is described by 10 parameters (A...J). Although these parameters are sufficient to describe a quadric surface located anywhere, for efficiency during rendering it is also useful to know the center and a bounding sphere. So by convention we require that (A...J) describe a surface centered at the origin, and add additional parameters x, y, z to add a translation component. Therefore a QUADRIC descriptor to render has the 17 parameters listed above.

The surface is the set of points for which Q(x,y,z) = 0 where

 Q(x,y,z) = Ax2 + By2 + Cz2 + 2Dxy + 2Eyz + 2Fzx + 2Gx + 2Hy + 2Iz + J

Points further from the origin (prior to translation!) than the limiting radius are not rendered.

Object type 15 - TMAT Isolation
Objects following this descriptor are interpreted as being in an absolute coordinate system centered at the origin and having unit extent in X, Y, and Z. If the image is rectangular, coordinates run from -0.5 to +0.5 along both X and Y. If the image is rectangular, coordinates run from -0.5 to +0.5 along the shorter dimension. The rotation and translation described by the TMAT matrix is not applied. This isolation from TMAT applies to subsequent objects until an object of type 9 is encountered.

Object type 16 - Global property
Object type 16 is always followed by a single record that affects the rendering of the entire scene. Currently the options are FOG, FRONTCLIP, and BACKCLIP. There are also options ROTATION and TRANSLATION that affect only objects following their appearance in the input stream.

Object type 17 - Vertex colours
Explicit vertex colours for preceding triangle or cylinder object.
    R1 G1 B1 R2 G2 B2 R3 G3 B3

Object type 18 - Vertex transparency
Explicit transparency at vertices of preceding object. All three values are required, though only the first two are used for cylinders, and only the first one for spheres.
    Trans1 Trans2 Trans3

Object type 19 - TMAT Isolation
Similar to object type 15, except the the x and y scales are the same only in the case of a square image. Both the x and y axes run from -0.5 to +0.5 regardless of the aspect ratio of the rendered image.

SEE ALSO
 PostScript and HTML documentation
 render(l)