R3D_OBJECTS(1)R3D_OBJECTS(1)NAME
Object types used by the Raster3D package
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 high‐
lighting 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 highlight‐
ing
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 ren‐
dered.
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 sur‐
faces of transparent spheres and cylinders
OPT2 Selects from several variant treatments of transparency as a func‐
tion 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 imme‐
diately. 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 docu‐
mentation)
Object type 9 - End_material
Terminates application of all previously defined special material prop‐
erties (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 light‐
ing 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 ther‐
mal 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 limit‐
ing radius are not rendered.
Object type 15 - TMAT Isolation
Objects following this descriptor are interpreted as being in an abso‐
lute 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 trans‐
lation described by the TMAT matrix is not applied. This isolation from
TMAT applies to subsequent objects until an object of type 9 is encoun‐
tered.
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, FRONT‐
CLIP, 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 val‐
ues 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)Raster3D 8 May 1999 R3D_OBJECTS(1)
