BILD is a simple text format that describes lines, polygons, and geometric primitives such as spheres, boxes, cylinders, and cones with commands (see example.bild). The commands are used to generate a VRML model in Chimera. The objects can be specified in absolute coordinates and/or transformed and scaled coordinates.
This file type is indicated by the filename suffix .bild or .bld, or by using bild:filename in the command line.
Square brackets denote optional parameters.
.arrow x1 y1 z1 x2 y2 z2 [r1 [r2 [rho]]]
Draw an arrow from (x1, y1, z1) to (x2, y2, z2). An arrow consists of a cylinder stretching from the initial point to an intermediary junction, and a cone stretching from the junction to the final point. The radius of the cylinder is r1 (default 0.1), the radius of the base of the cone is r2 (default 4*r1), and the fraction of the total distance taken up by the cylinder is rho (default 0.75).
.box x1 y1 z1 x2 y2 z2
Draw a box with opposite corners at (x1, y1, z1) and (x2, y2, z2).
.color name
or
.color r g b
Set the color of subsequently defined items. The name can be a built-in name, a name defined previously with colordef, or an integer that refers to the old BILD color wheel (0-65, inclusive). Alternatively, a color can be described by its red (r), green (g), and blue (b) components, each in the range 0-1, inclusive.
.cone x1 y1 z1 x2 y2 z2 r [open]
Draw a cone with a base of radius r centered at (x1, y1, z1) and a tip at (x2, y2, z2). If the keyword open is present, the base of the cone will be invisible.
.cylinder x1 y1 z1 x2 y2 z2 r [open]
Draw a cylinder with radius r and bases centered at (x1, y1, z1) and (x2, y2, z2). If the keyword open is present, the bases of the cylinder will be invisible.
.dotat x y z
or
.dot x y z
Draw a sphere of unit radius centered at (x, y, z). The sphere center is treated as a vertex if there is a subsequent .draw, .drawrel, or .moverel command.
.draw x y z
or
.d x y z
Add another vertex to the current set of line segments. A line will be drawn from the previous vertex to this vertex at (x, y, z). There should be a prior .move, .moverel, .dotat, or .marker command (these initiate sets of line segments).
.drawrel dx dy dz
or
.dr dx dy dz
Add another vertex to the current set of line segments. A line will be drawn from the previous vertex at (x, y, z) to this vertex at (x + dx, y + dy, z + dz).
.marker x y z
Draw a box of unit cubic diagonal centered at (x, y, z), i.e., a box with opposite corners at (x – 0.5, y – 0.5, z – 0.5) and (x + 0.5, y + 0.5, z + 0.5). The box center is treated as a vertex if there is a subsequent .draw, .drawrel, or .moverel command.
.move x y z
or
.m x y z
Start a new set of line segments whose first vertex is at (x, y, z).
.moverel dx dy dz
or
.mr dx dy dz
Start a new set of line segments whose first vertex is at (x + dz, y + dy, z + dz), where (x, y, z) is the coordinate of the last vertex defined.
.polygon x1 y1 z1 x2 y2 z2 ... xN yN zN
Draw a flat polygon with vertices at (x1, y1, z1), (x2, y2, z2), ..., (xN, yN, zN).
.pop
Discard the most recent transformation (rotation, scaling, or translation) from the transformation stack.
.rotate angle axis
or
.rot angle axis
Rotate all subsequent coordinates by the given angle (in degrees) about the given axis (x, y, or z). This transformation is added to the top of the transformation stack.
.scale xscale [yscale [zscale]]
Scale all subsequent coordinates by the given factor(s). The x coordinates will be scaled by xscale, y coordinates by yscale (equal to xscale by default), and z coordinates by zscale (equal to xscale by default). This transformation is added to the top of the transformation stack.
.sphere x y z r
Draw a sphere centered at (x, y, z) with radius r.
.translate dx dy dz
or
.tran dx dy dz
Translate all subsequent coordinates by the specified amount. This transformation is added to the top of the transformation stack.
.vector x1 y1 z1 x2 y2 z2
or
.v x1 y1 z1 x2 y2 z2
Draw a line segment from (x1, y1, z1) to (x2, y2, z2). This command is a shorthand for.m x1 y1 z1
.d x2 y2 z2