graphics

The graphics command draws low-level graphics primitives. These primitives can be used to draw a box around a molecule, or an arrow between two atoms, or place a text label somewhere in space. The command syntax is graphics <molid> <cmd>, where <molid> is a valid molecule id and <cmd> is one of the commands listed below. To create a ``blank'' molecule, use the Tcl command mol new. See the draw command for a possibly more convenient interface. Also refer to the VMD script library for some examples of user-defined graphics scripts.

As graphical primitives are added to the list they are assigned a unique, increasing id. The first object added is assigned 0 , the second is assigned $1$ , etc. The commands which add an item return its value.

• point {x y z}: Draws a point at the given position.

• line {x1 y1 z1} {x2 y2 z2} [width w] [style $<$ solid|dashed$>$ ] :

  Draws either a solid or dashed line of the given width from the first point to the second. By default, this is a solid line of width 1.

• cylinder {x1 y1 z1} {x2 y2 z2} [radius r] [resolution n] [filled $<$ yes|no$>$ ]:

  Draws a cylinder of the given radius (default r$=$ 1) from the first point to the second. The cylinder is actually drawn as an n sided polygon. If the filled option is true, the ends are capped with flat disks, otherwise the cylinder is hollow (default). width of the base. The resolution parameter (default n$=$ 6) determines the number of polygons used in the approximation.

• cone {basex basey basez} {tipz tipy tipz} [radius r] [resolution n]:

  Draw a cone with the center of the base at the first point and the tip at the second. The radius(default r$=$ 1) determines the width of the base. As with cylinder, the resolution (default n$=$ 6) determines the number of polygons used in the approximation.

• triangle {x1 y1 z1} {x2 y2 z3} {x3 y3 z3}:

  Draws a triangle with endpoints at each of the three vertices

• trinorm {x1 y1 z1} {x2 y2 z3} {x3 y3 z3} {nx1 y1 z1} {nx2 ny2 nz3} {nx3 ny3 nz3}:

  Draws a triangle with endpoints at each of the first three points. The second group of three values specify the normals for the three points. This is used for making a smooth shading across the triangle. The normals must be normalized to unit-length for proper display.

• tricolor {x1 y1 z1} {x2 y2 z3} {x3 y3 z3} {nx1 y1 z1} {nx2 ny2 nz3} {nx3 ny3 nz3} c1 c2 c3:

  Draws a triangle with endpoints at each of the first three points. The second group of three values specify the normals for the three points. The last three integers indicate the colors to apply to each vertex. This is used for making a smooth shading across the triangle. The normals must be normalized to unit-length for proper display.

• sphere {x y z} [radius r] [resolution n]:

  Draws a sphere of the given radius (default r$=$ 1) centered at the vertex. The resolution (default n$=$ 6) determines how many polygons are used in the approximation of a sphere.

• text {x y z} ``text string'' [size s] [thickness t]:

  Displays the text string with the bottom left of the string starting at the given coordinates, with the font size scaled by the optional size parameter, and drawn with line thickness determined by the optional thickness parameter.

• color colorId
• color name
• color trans_name: Each of the above geometrical objects are drawn using the current color. Initially, that color is blue, which has the colorid of 0. The color command changes the current color, and stays info effect until the next color command. Thus, to draw a red cylinder then a red sphere, first use the command color red command to change the color, then use the cylinder and sphere commands.

• materials $<$ on|off$>$ : Material properties are used to make the graphical objects (lines, cylinders, etc.) be affected by the light sources. These make the objects look more realistic, but are slower on machines which don't implement materials in hardware (see chapter 6.2 and sections on color and colorinfo commands for the information on how to turn off material characteristics for all objects in VMD). One surprising effect of material characteristics is that lines are affected. In some lighting situations, the lines can even appear to disappear. Thus, you may want to turn off materials before drawing lines.

• material $<$ name$>$ : Sets the material to use for the corresponding graphics molecule. name must be a valid material name, as displayed in the Materials menu.

• delete id: Deletes the graphics primitive with the given id.
• delete all: Deletes all graphics primitives.
• replace id: Causes the next graphics primitive to replace the one with the given id. Subsequent graphics primitives will be added to the end of the list as usual.
• exists id: Returns whether the primitive with the given id exists.
• list: Returns a list of valid graphics id's.
• info id: Returns the text of a Tcl command which will recreate the graphics primitive with the given id.