Description of FFE Menus¶
Force Field Explorer currently reads Tinker coordinate files (XYZ, INT), restart files (DYN), archive files (ARC), induced dipole files (file suffix ending in “u”) and Protein Databank files (PDB). Currently, file writing us only implemented for Tinker XYZ coordinate files.
An attempt is made to open the selected file. Currently, Tinker XYZ coordinate files, Tinker archive files, and Protein Databank files are recognized.
Saves the active file under a different name. Currently, this command is currently only supported for Tinker XYZ coordinate files.
Close the active file.
Close all open files.
Download from PubChem…
Entering a valid molecule name downloads the corresponding structure from the NIH PubChem database, convert atom types to the “tiny” force field, and save the Tinker XYZ file to the NIH Downloads directory, then open it.
Download from NCI…
Entering a valid molecule name downloads the corresponding structure from the NCI Cactus database, convert atom types to the “tiny” force field, save the Tinker XYZ file to the NIH Downloads directory, then open it.
Download from PDB…
Entering a valid 4 character accession downloads the corresponding PDB file, save it to the current Force Field Explorer working directory, then open it.
Choose Key File…
Allows selecting a specific, non-default Tinker KEY file containing options for the selected molecular system.
Choose Log File…
Allows selectiong a specific Tinker LOG file that will be displayed in the FFE Log panel.
Load Restart Data…
Tinker Restart files (DYN) contain atomic positions, velocities and two sets of accelerations (current and previous step), but no connectivity information. Loading a Restart file on top of an open Tinker coordinate file allows visualization of velocities and accelerations.
Load Induced Data…
Tinker Induced Dipole files (end in “u”) contain induced dipole vectors. They are produced during a molecular dynamics routine using the Tinker “save-induced” keyword. Loading an Induced Dipole file on top of an open Tinker coordinate file allows visualization of induced dipoles.
Choose Tinker Location…
Allows specifying a location for the Tinker executables to be used with Force Field Explorer. The default is to use the executables bundled with the install kit and present under $HOME/Tinker-FFE.
Exit shuts down Force Field Explorer, after saving user preferences.
The set of nodes currently selected are highlighted in the Molecular Tree. If the shift key his pressed while clicking on two nodes, all nodes in between are selected. Alternatively, by holding down the control key while clicking on a node, either in the Tree or Graphics window, the selection state of a node can be toggled. To use Graphics based picking, the Graphics Picking checkbox under the Picking menu must be selected.
All open systems are selected.
Restrict to Selections
Nodes that are not selected are made invisible.
Selected nodes are highlighted in the Graphics window.
Set Selection Color…
Choose the color for selected atoms.
Label Selected Atoms
Selected atoms are labeled by number and description.
Label Selected Residues
Selected residues are labeled by their respective three letter identifiers.
Set Label Font Size
The default label size is 12 point.
Set Label Font Color…
The default font color is white.
We have intentionally maintained a simple, but elegant rendering mechanism. The Force Field Explorer data structure is self-rendering, meaning that each object “knows how to draw itself”. Rendering commands are “Top-Down”, meaning that commands filter down through the molecular tree, with each node responding and/or passing commands to its children. This paradigm positions Force Field Explorer to easily scale up to multi-level molecular engineering/nanotechnology modeling projects. The intent is to avoid is a rendering/data architecture built upon “an array of atoms”. In our opinion, “an array of atoms” infrastructure does not achieve our molecular engineering design goals. While a graphics change is being rendered, one additional graphics command will be cached. Other commands are ignored while the 3D view catches up. Changes are applied to all selected nodes in the Molecular Tree View.
Represents the selection as a collection of thin lines for bonds.
Represents the selection as a collection of bond tubes of medium diameter. This option can be slow for systems with more than a few thousand atoms.
Represnets the selection as a collection of overlapping atoms of large diameter proportional to their vdw radii.
Ball & Stick
Represents the selection as a collection of atoms of medium diameter and thin tubes for bonds. This options can be slow for large systems with more than a few thousand atoms.
Removes any graphical representation of the selected system or subsystem.
Similar to Spacefill, but the sphere sizes are set to the Lennard-Jones minima for each atom in the system.
Fill rendered polygons.
Render only vertices.
Render edges between vertices.
Preferences… –> Radius
A scale factor applied to all rendered spheres and cylinders.
Preferences… –> Wireframe Thickness
This specifies the thickness of wireframe representations in pixels.
Preferences… –> Detail
Changes the number of vertices used in creating spheres and cylinders. More vertices (a higher number on the slider) create a smoother appearance, but slower rotations.
Black & White rendering.
Atom based colors.
Color based on amino/nucleic acid.
Color based on secondary structure specified in PDB files.
A different color is assigned to each polymer.
Coloring is based on partial charges that correspond to atom types specified in Tinker coordinate files.
Coloring is based on vector magnitude, where the vector may represent velocity, acceleration, induced dipole or force depending on user choice.
Arbitrary colors can be assigned to selected atoms by choosing the “Apply User Color to Selections” menu item. The “User Color” can then be selected to invoke this scheme.
Apply User Color to Selections
Applies the currently active User Color to the selected atoms.
Set User Color…
Specify the color to use when selecting the “Apply User Color to Selections” option.
Coordinate controls for the active system.
Removes any rotations applied to the active system.
Removes any translation applied to the active system.
Reset Rotation and Translation
Removes any rotation/translation applied to the active system.
Rotate About Center of Mass
Specifies the active system should be rotated about its center of mass.
Reset About Pick
Specifies the active system should be rotated about the node selected by graphics picking.
Specify which system is controlled by mouse clicking/dragging within the Graphics window.
Regardless of mouse position, the Active system is controlled.
System Below Mouse
To move a system, it must be picked by clicking over it with the mouse.
Reset Global Zoom
Reset the global zoom that has been applied to the entire scene.
Reset Global Translation
Remove any global translation that has been applied to the entire scene.
Reset Global Rotation
Remove any global rotation that has been applied to the entire scene.
Reset Global View
Remove any global rotation and translation, then reset the global zoom.
Show/Hide hydrogen atoms.
Make the graphics window fill the entire screen.
Set Background Color…
Change the color of the graphics window background. This is useful for switching to a white background before capturing images that might be printed.
Graphics picking can be used to select nodes anywhere in the structural hierarchy. By holding the control key while picking, the selection state of the picked node is toggled between selected/not selected. However, holding the shift button down while picking currently has no effect.
Selecting this checkbox turns on Graphics Picking.
An individual Atom will be picked.
A Bond will be picked, with consecutive clicks cycling through all Bonds made by the picked atom.
An Angle will be picked, with consecutive clicks cycling through all Angles made by the picked atom.
A Dihedral will be picked, with consecutive clicks cycling through all Dihedrals made by the picked atom.
An individual Residue from a biopolymer will be picked.
An individual Polymer chain will be picked.
An individual Molecule will be picked.
An individual System from among those currently loaded will be picked.
After selecting two atoms the distance between them will be reported in the Force Field Explorer console.
After selecting three atoms the angle formed between them will be reported in the Force Field Explorer console.
After selecting four atoms the dihedral formed between them will be reported in the Force Field Explorer console.
Set Graphics Picking Color…
Picked nodes will be highlighted in the color selected using this control.
Tinker trajectories are stored in Archive files (ARC), which are simply a concatenation of Tinker coordinate files (XYZ, INT).
When the end of a trajectory is reached, it is played in the reverse direction instead of restarting at the beginning.
Advance to an arbitrary frame of the active trajectory.
Choose a frame rate for trajectory playback. If 20 frames per second is entered, for example, a delay of 50 msec between coordinate changes is enforced. Therefore, the actual frame rate will be slower than what is specified if rendering for the system is slow.
Instead of displaying every frame during trajectory playback, only every nth frame will be rendered.
Play the active trajectory.
Stop the active trajectory.
Advance the active trajectory one frame.
Rewind the active trajectory one frame.
Return the active trajectory to the first frame.
Tinker molecular dynamics, optimization and sampling methods are configured to start a server that listens for Force Field Explorer clients. Once a client-to-server connection is established, simulation information can be sent between Tinker and Force Field Explorer. Multiple Force Field Explorer clients can connect to the same Tinker simulation.
If Force Field Explorer is connected to a Tinker simulation, the connection will be closed.
Connect to Local Job
Force Field Explorer will attempt to connect to a Tinker simulation executing on the current computer.
Connect to Remote Job
Force Field Explorer will attempt to connect to a Tinker simulation executing on a remote computer.
Set Remote Job Address…
Specify the IP address of the remote computer where a Tinker simulation is executing. No domain name server is used, so the address should be of the form: XXX.XXX.XXX.XXX
Specify the port number to be used for connection to a Tinker simulation.
Currently, Force Field Explorer can save screenshots in PNG, JPEG, BMP and GIF formats. In most cases, PNG gives better image quality when using Force Field Explorer than JPEG, likely because the default JPEG configuration use prioritizes small image size over preservation of detail.
Capture the Graphics window to an image file.
Use the PNG image format to render Graphics output.
Use the JPEG image format to render Graphics output.
Use the BMP image format to render Graphics output.
Use the WBMP image format to render Graphics output.
Use the GIF image format to render Graphics output.
Force Field Explorer components can be customized to some extent to suit user preferences. Many user configurable choices are saved between sessions.
This resets the slider between the Molecular Tree and Graphics Windows to the default position. The Graphics window is a heavy weight component (so hardware graphics acceleration can be used), while most Force Field Explorer components are light weight “Swing” components. Unfortunately, this effect prevents the user from dragging the slider and shrinking the Graphics window.
Show/Hide the Tree view.
Show Tool Bar
Show/Hide the Tool Bar.
Show Global Axes
Show/Hide the Global Axes. The Global Axes are used both as a visual cue and to affect global rotations and translations.
Resets the FFE command line Console.
Ocean Look & Feel
This appearance should cause Force Field Explorer to more closely resemble the native platform. In addtion, top bar menu items will be moved to the main FFE application window. The default appearance is “Java Metal”, which should be consistent across platforms.