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Command: save

saveimage | session | map ]  filenameformat  format-name ] [ models  model-spec ]  other-options

save formats

The save command saves an image, ChimeraX session, map (volume data), atomic coordinates, sequences, or other data to filename, which can be a pathname including the directory location. The pathname can be absolute or relative to the current working directory as reported by pwd. The working directory can be changed with cd. Giving the word browse instead of a filename opens a file browser window for choosing it interactively. Files can also be saved with menu File... Save or Toolbar icon . See also: open, log, Writing mmCIF Files in ChimeraX

An initial image, session, or map keyword before the filename is optional if the file type is specified with either the filename suffix or the format option. Some file types have no preceding keyword and must be specified with the filename suffix or the format option. If the format is specified separately, the appropriate suffix will be added to filename.

Sessions and images include all contents, but for other file types, the models option can be used to specify which model(s) to save. There may be several additional options, depending on the file type:

Output Formats

The command save formats lists the possible output formats in the Log.

initial keyword format-name filename suffix description
image png
(default for save image)
.png Portable Network Graphics
tiff .tif
Tagged Image File Format
jpeg .jpg
Joint Photographic Experts Group
gif .gif Graphics Interchange Format
bmp .bmp bitmap
ppm .ppm Portable PixMap
session session .cxs ChimeraX session
map cmap .cmp
Chimera map
(may contain multiple models)
dsn6 .brix BRIX density map
mrc .mrc MRC density map
(none) pdb .pdb atomic coordinates,
(see Save PDB)
pseudobonds .pb list of atom pairs to connect with pseudobonds
(see the selectedOnly option)
mmcif .cif atomic coordinates,
(see Save mmCIF)
mol2 .mol2 atomic coordinates,
Sybyl Mol2
(see Save Mol2)
dcd .dcd trajectory coordinates,
DCD (binary)
markers .cmm markers and links
(analogous to atoms and bonds)
gltf .glb 3D objects, GL Transmission Format
(see glTF options)
stl .stl 3D objects, STereoLithography
obj .obj 3D objects, Wavefront OBJ
(geometric and texture vertices, vertex normals, faces; no colors)
x3d .x3d 3D objects, X3D
aln .aln, .clustal
.clustalw, .clustalx
biopolymer sequence or sequence alignment,
Clustal ALN
fasta .fasta, .fa
.afasta, .afa
biopolymer sequence or sequence alignment,
pir .pir, .ali biopolymer sequence or sequence alignment,

Save Image

Usage: saveimage ]  filenameformat  format-name ] [[ width  w ][ height  h ] | pixelSize  p ] [ supersample N ] [ quality M ] [ transparentBackground  true | false ]

Images generally have the same contents as the graphics window, but are rendered offscreen. See also: windowsize, view, making images, making movies,

width  w ][ height  h ] | pixelSize  p
Image pixel dimensions can be specified directly with width and height, or relative to the physical dimensions of the view in the window with pixelSize. If none of these are given, the image will have the same pixel dimensions as the graphics window. If only width or height is specified, the other will be set according to the window aspect ratio; if both are specified but the image aspect ratio is not the same as the window aspect ratio, the image contents will differ from what is shown in the window. With the pixelSize option, the image contents will be the same as what is shown in the window, but image pixel dimensions will be chosen to give pixels of size p in Å. With perspective, the pixel size varies with depth, but pixelSize sets the value at half-depth (the midpoint along the line of sight). For example, if at half-depth the graphics window encloses a 400-Å by 300-Å rectangle, pixelSize 0.4 specifies image pixel dimensions of 1000 by 750.
supersample N
Supersampling refers to initially generating an image at a higher resolution than requested and then sampling it down to the final size. This gives a smoother (less pixelated) appearance of lines and boundaries in the final image. The degree of supersampling N defaults to 3, meaning that the initial image will be 3 times larger in each dimension, with 9 times as many pixels, as the final result. A value of 1 corresponds to no supersampling. See also: graphics quality
quality M
The quality M applies to JPEG format only, with values in the range 0–100 (default 95).
transparentBackground  true | false
Whether to include opacity values (alpha) in an output PNG or TIFF file. With background transparency, the background will be completely invisible in the saved images. This facilitates combining the image with different backgrounds in image-editing applications. (Note: TIFF images with background transparency may not be interpreted correctly by Adobe Photoshop.)

Save Session

Usage: savesession ]  filenameformat  format-name ] [ includeMaps  true | false ]

A ChimeraX session file encodes most aspects of a modeling session in ChimeraX, including atomic and other models, sequences, camera views, lighting, display styles, coloring, labels (2D and 3D), selections, selection highlighting color and width, attributes, custom colors, custom button panels, aliases, defined targets, surface zones, and segmentation results. Saving and later opening a session file restores the session and allows resuming work in ChimeraX. A common use is to store setups for figures and movies. Whether to restore the graphics window size when opening a session file is set in the Window preferences or can be specified with the open command resizeWindow option. See also: ChimeraX command files

Sessions are saved in a ChimeraX-specific format not read by other programs. Maps generated on the fly (rather than read from a file) are always included if present, but the includeMaps option indicates whether maps read from pre-existing files should also be included. The default is false, as maps can be very large. If the maps are not included, the session file will still include the locations of the corresponding map files and open them automatically upon session restore, or if they are not found, prompt the user for their current locations.

Save Map

Usage: savemap ]  filenamebaseIndex M ] [ format  format-name ] [ models  model-spec ] [ step  N | Nx,Ny,Nz ] [ region  all | name | i1,j1,k1,i2,j2,k2 ] [ maskZone  true | false ] [ append  true | false ] [ compress  true | false ] [ chunkShapes  order ]

Various formats are available for saving maps (volume data). MRC files written by ChimeraX are in the MRC 2000 format. Older MRC-reading programs or programs expecting CCP4 format will read such files successfully but may not align the data correctly with other data sets. Only the Chimera map format can accommodate multiple data sets in a single file. Multiple data sets can be written to multiple files by including a %d integer format specification in filename:

save #2,3,7 data%d.mrc
save #2,3,7 data%03d.mrc

The first example would generate the files data1.mrc, data2.mrc, and data3.mrc, while the second would instead use names like data001.mrc. Successive integers starting with baseIndex M (default 1) will be used in the new names regardless of the volume model numbers. If the format specification is incorrect, filename will be interpreted as the name of a single file.

Further options:

models  model-spec
Volume model(s) to save; can be omitted if only one volume model is open.
step  N | Nx,Ny,Nz
Whether to use the full resolution of the data (step size 1, default) or a specified subsample (step size > 1). Step sizes must be integers. A step size of 1 indicates all data points, 2 indicates every other data point, 3 every third point, etc. If a single number is supplied, it is used along all three axes; if three numbers are supplied (separated by commas but not spaces), they are used along the X, Y, and Z axes, respectively.
region  all | name | i1,j1,k1,i2,j2,k2
Whether to write the full extents of the data (all, default) or a specified subregion. A subregion can be specified by name (previously assigned with volume) or by grid indices i1–i2 along the X axis, j1–j2 along the Y axis, and k1–k2 along the Z axis. Grid indices must be integers separated by commas but not spaces. If the region option is not supplied, the currently displayed subregion will be written. In this context, a zone is not considered a subregion.
maskZone  true | false
If zoning is in effect (see surface zone), whether to write out data for a region enclosing the zone, with values outside the zone set to zero. See also: volume zone

If Chimera map format is saved:

Compression is most useful for volume masks (values 0/1), as other data sets tend to be noisy and compress very little, if at all. Layout affects the efficiency of later reading the data, primarily a concern for very large data sets (hundreds of Mb). The chunkShapes order can be one or more of the following, separated by commas but not spaces:

Data are written in blocks of up to 64 Kb. The blocks are shaped according to the specified order: smallest along the first axis and largest along the third. Data planes are read from a file with different efficiencies depending on their orientations and the layout. For example, from data written in the default order (zyx), XY planes will be read the most efficiently and YZ planes the least efficiently. When multiple orders are specified, multiple copies of the data are written to the same file. When the file is read, the most efficient copy available will be used. Saving a file with an order ending in “z” can be very slow because one Z-plane is written at a time.

Save PDB

Usage: save  filenameformat  pdb ] [ models  model-spec ] [ relModel  model-spec ] [ selectedOnly  true | false ] [ displayedOnly  true | false ] [ allCoordsets  true | false ] [ pqr  true | false ] [ serialNumbering  amber | h36 ]

Atomic coordinates can be saved in PDB format. The filename can include [NAME] and/or [ID] to indicate substitution with model name and/or model number, respectively, as needed to save multiple atomic models to multiple files with a single command. See also: getcrd, view

models  model-spec
Write only the specified models, otherwise all atomic models.
relModel  model-spec
Write coordinates relative to the original coordinates of the specified model. Otherwise, coordinates will be written relative to the scene (same as the original coordinates of each model unless it was moved separately). Saving a model relative to another is useful for preserving their spatial relationship without having to save copies of both models. For example, if model 2 has been matched or docked to model 1 (such as with matchmaker, align, or fitmap), saving model 2 relative to model 1 results in them being matched or docked in the same way when the original model 1 file and the new model 2 file (saved relative to 1) are opened.
selectedOnly  true | false
Whether to include only the selected atoms when saving a PDB file, or only the selected pseudobonds when saving a pseudobond file.
displayedOnly  true | false
Whether to include only the displayed atoms. Note that cartoon display does not imply atomic display, and conversely, backbone atoms may be displayed but suppressed by cartoon.
allCoordsets  true | false
Whether to save all frames (coordinate sets) of a trajectory or just the frame that is currently displayed (default). Saving all frames produces a multi-model PDB file.
pqr  true | false
Whether to generate PQR format instead of standard PDB. In PQR format, atomic partial charge (Q) and radius (R) fields follow the X,Y,Z atomic coordinates.
serialNumbering  amber | h36
How to accommodate structures so large that the numbering fields in standard PDB format would overflow (output for smaller structures is not affected):

Save mmCIF

Usage: save  filenameformat  mmcif ] [ models  model-spec ] [ relModel  model-spec ] [ selectedOnly  true | false ] [ displayedOnly  true | false ]

Atomic coordinates and associated information can be saved in mmCIF format. A subset of the mmCIF data types are written (details...). The options are as described for saving PDB.

Save Mol2

Usage: save  filenameformat  mol2 ] [ models  model-spec ] [ relModel  model-spec ] [ combineModels  true | false ] [ atoms  atom-spec ] [ skipAtoms  atom-spec ] [ anchor  atom-spec ] [ sybylHydNaming  true | false ] [ resNum  true | false ] [ gaffType  true | false ]

Atomic coordinates can be saved in Sybyl Mol2 format, with options:

models  model-spec
Write only the specified models, otherwise all atomic models (except as restricted with atoms and/or skipAtoms).
relModel  model-spec
Write coordinates relative to the original coordinates of the specified model (as described above for PDB).
combineModels  true | false
Whether to write multiple models into one combined @MOLECULE section. If false (default), separate @MOLECULE sections will be used for different models.
atoms  atom-spec
Write only the specified atoms.
skipAtoms  atom-spec
Skip (omit) the specified atoms.
anchor  atom-spec
Write the specified atoms into the @SET section of the file.
sybylHydNaming  true | false
If true (default), hydrogen names will be of the form HG21 instead of 1HG2.
resNum  true | false
Whether to append residue number to reside name, giving substructure names of the form ALA85 instead of ALA (default false).
gaffType  true | false
Whether to write GAFF atom types instead of Sybyl atom types. GAFF types are not yet computed, so this should be kept false.

Save Sequence Data

Usage: save  filename format  fasta | pir ] [ alignment  alignment-id ]

Only the contents of a single Sequence Viewer window can be saved to a file at a time. When more than sequence window is present, the alignment option is needed to specify the window of interest, using the alignment-id shown in the title bar of the window. Example:

save example.pir alignment 1.A


Usage: save  filenameformat  gltf ] [ center  x,y,z ] [ size  s ] [ shortVertexIndices  true | false ] [ floatColors  true | false ] [ preserveTransparency  true | false ]

Several options apply only to saving GL Transmission Format (.glb):

center  x,y,z
Origin coordinates for the exported objects.
size  s
Bounding size for the exported objects. The coordinates are scaled so that the longest edge of the bounding box becomes the specified size.
shortVertexIndices  true | false
Whether vertex indices in the exported file must fit within 16 bits (0-65535).
floatColors  true | false
Whether to use floating-point color values.
preserveTransparency  true | false
Whether to include any transparency of the objects.

UCSF Resource for Biocomputing, Visualization, and Informatics / September 2019