Running the app¶

VisFEM runs as a local web server which the browser connects to; the visfem command starts it and prepares the datasets it shows.

Launching¶

visfem

starts the web app and opens it in the browser. visfem without a command is the same as visfem serve, which accepts the options of the trame server:

visfem serve --server --port 9000     # no browser, fixed port
visfem serve --host 0.0.0.0           # listen on all interfaces of the machine
visfem serve --help                   # every option of the trame server

The server listens on localhost by default. A single visfem serve process is one session which every connected browser shares; a public instance runs behind the trame launcher, which starts one process per visitor, see Deployment.

Data directory¶

VisFEM shows the datasets of a data directory. It reads the datasets/ folder inside the directory that DATA_DIR names:

export DATA_DIR=/path/to/your/data    # datasets are read from /path/to/your/data/datasets
visfem

Without DATA_DIR, a checkout of the repository uses its own data/ folder and an installed VisFEM uses ./visfem_data in the working directory, where the fetch commands of the example data put their datasets. How a dataset is laid out is described in Datasets.

Environment variables¶

variable	effect
`DATA_DIR`	data directory, the datasets are read from its `datasets/` folder; `VISFEM_DATA_DIR` is an alias
`VISFEM_DATASETS`	comma separated allowlist of dataset keys, e.g. `heart,ircadb`; the other datasets stay hidden. Empty shows every dataset
`VISFEM_LOG_LEVEL`	level of the log output, e.g. `DEBUG` or `INFO`; the default is `WARNING`
`VISFEM_PRELOAD`	`1` loads every mesh into memory at startup, so the first selection of a dataset does not wait for the disk

Opening a dataset by link¶

The model query parameter, or its alias dataset, selects a dataset when the app opens, e.g. app.visfem.de/?model=heart. The value is the key of the dataset, i.e., the file name of its JSON descriptor without .json. The tiles of the landing page link to the models this way.

Command line¶

Besides serve, the visfem command documents, scaffolds and validates datasets and downloads the example data:

command	purpose
`visfem renderers`	the built-in renderers and what each one draws
`visfem schema`	the fields of a dataset descriptor
`visfem example <renderer>`	a minimal valid descriptor for a renderer
`visfem new-dataset <name> --renderer <renderer>`	scaffold `datasets/<name>/` with a descriptor template
`visfem validate-data`	validate every descriptor and check that the files it references exist
`visfem fetch-ircadb`	download the 3D-IRCADb-01 dataset, see Example data
`visfem fetch-openknee`	download the Open Knee(s) geometries, see Example data

visfem <command> --help lists the options of a command.