Assets and resources¶

Assets are .DAVE files containing one or more Nodes. These are human readable python files. Resources are all files that DAVE can use in a model. For example visuals (.obj), hydrodynamic databases but also assets (.DAVE).

Assets¶

Re-usable components of a model are typically stored as asset. Assets can be imported into a scene using import_scene or via the Library in the Gui.

Library

If a model contains many identical parts, it is good practice to save these parts as asset.

Example:

Consider a 4 point lift with four identical pad-eyes.

Model the padeye:

First create a single padeye.
Then save this padeye as asset.

Model the lift:

Create the lifted object
Import the padeye asset and place it on the lifted object
Repeat for the other three padeyes.
Import the hook asset.
Model slings and shackles.

To avoid name conflices assets can be imporeted using a pre-fix on the element names. To enable movement and rotation of the imporeted nodes as a whole it is possible to place all imported elements in an axis (container). This means all positions and rotations are given relative to this axis. Moving and rotating this axis will move/rotate all contained nodes.

Resources¶

Some default resources are included with DAVE. These include basic geometric shapes, shackles and the famous DAVE fleet. You can add your own.

Storage locations¶

DAVE is designed with use as part of a larger system in mind. In such a system various sources for assets and resources may exist. For example a shared library with officially approved assets, an library with project assets that are still under construction, a personal folder with the items you are working on at that moment.

On the other hand, DAVE can also be used completely separated from the rest of the world.

Assets and resources are FILES on a file-system somewhere. Assets are files with a .DAVE extension and can be imported into a scene or can be opened as a scene. Resources are all other type of files that may be needed such as .obj or .stl files for visuals or buoyancy, hydrodynamic databases and so on.

A Scene contains a list of locations where assets and resources can be found. This list is in Scene.resources_paths. By default it is initialized (in settings.py) to

the resources subdirectory in the DAVE python source folder
the DAVE_models subdirectory in the users home folder.
the current work directory

You are free to add more locations or remove existing locations by either changing the initilization in settings.py for a system-wide change or by changing the resources_paths list of the current Scene object.

The order of the list is important. The list is considered to be ordered from most-official to least-official. So, for the default list, a resource in the resources subfolder of the DAVE installation is considered of higher rank than a resource with the same name in the users DAVE_assets folder.

More info:

For information about python lists see python documentation
Python treats backslashes “” in strings in a special way which can result in unexpected results when you are not aware of that. For example \n means “new-line” and \t means tab. To suppress this simply place a “r” in front of the string.

s = Scene()
s.resources_paths.append(r'c:\data') # append to the end of the list
s.resources_paths.insert(0, r'c:\data\copy_of_very_official_stuff') # insert at top of list
s.resources_paths = [r'c:\master_assets', *s.resources_paths] # alternative to insert on top of list.

In a typical workflow an asset would first be created in a local or project folder. Then it would be checked as approved. Once approved it would be moved to an official (write protected) folder.

Loading and saving resources¶

The path to a resource can be obtained using Scene.get_resource_path(name). This will loop over the resources_paths from top to bottom. It will return the full path to the first items found. More official assets or resources take precedence over less official ones.

If a resource with the same name is present in both the resources directory and the DAVE_models directory then a link to the one in the resources directory is returned.

When saving resoures the folders are evaluated from bottom to top. The first folder with write access is used to save the item. So this is exactly opposite from loading resources. A resource is saved in the least official folder.

It is also possible to load or save resources using the full path. In that case the whole system is circumpassed.

Subfolders¶

The Scene object will not walk through sub-folders when looking for an asset or resource. This means that subfolders add to the uniqueness of the filename. A file called attempt1/box.obj is different from a file attempt2/box.obj

Examples¶

Example

s = Scene()
filename = s.get_resource_path('buoyancy cheetah.obj')  # will return the official buoyancy cheetah.obj

s.save_asset('empty')                 # assets saved in workfolder / empty.dave
s.save_asset('subfolder/empty')       # assets saved in workfolder / subfolder / empty.dave

s.get_resource_path('empty.dave')           #  will return "workfolder / empty.dave_asset"
s.get_resource_path('subfolder/empty.dave_asset') #  will return "workfolder / subfolder / empty.dave"

s.save_asset(r'c:\data\test.abc')     # will save as c:\data\test.abs

Summary¶

Scene.resources_paths is a list of paths with locations where resources are located.
This list is ordered from Most official to Least official
If a file with the same name exists in a more official location, then that file gets priority above a file with the same name in a less official location.
Saving files without specifying the full path will store them in the least official folder
The resources_paths can be edited either in settings.py or in the Scene object.