Overview

Nested INI Files

The ABR pipeline is configured using nested ini files. Nested ini files look exactly like regular ini files, but allow for nested namespaces.

For instance, the following code example

[namespace]
subnamespace.one = 1
subnamespace.two = 2
subnamespace.three = 3

is identical to

[namespace.subnamespace]
one = 1
two = 2
three = 3

Although this disallows '.' in identifiers, this is practical when information needs to be grouped in certain ways.

For instance, loading additional parts and objects into scenarios makes use of nested namespaces for documentation purposes. You might want to add a certain part or object from a blender file such that you can specify textures or material properties directly within blender. However, your downstream application such as a deep network for pose estimation only understands PLY files and does not care about material properties. However, PLY files often use a scaling, e.g. in mm, that is different from what you might use in blender, e.g. m. To group all of this information, we make use of the following canonical way to describe parts that we load from an ini file:

[parts]
partname = /path/to/partname.blend
ply.partname = /path/to/partname.ply
ply_scale.partname = 0.010

Note that some configuration files, such as the Workstation Scenarios configuration, allow additional/extended specifications. Details about these are described in their corresponding documentation.

ATTENTION: when scaling objects, the final behavior might be different between loading objects from .blend or from .ply since the intrinsic scales might be different within the two files. Anyway, for scaling objects load from .blend files use the corresponding blend_scale.partname config tag. Similarly, loading from ply use the ply_scale.partname config tag.

Important Notes.

For this to work properly, make sure that your parts have the correct scale, as well as rigid object properties. In particular, do not forget to make (in the blender file) the object an active rigid object with appropriate weight and margins for sensitivity.

Also, make sure that the object’s center is approximately at its real-world physical center. Often, PLY models don’t have the object center at the physical or geometric center of the object. To quickly change this in blender, select the object and, in object mode, go to the toolbar “Object” -> “Set Origin To” and select an appropriate variant. Afterwards, it is best to move the object to location 0, 0, 0. Note that for the provided objects we moved the center to the geometrical center, as this is the most common usage in downward applications such as neural networks.

In the provided scenes, we currently use a default weight of 0.01kg for most (small) objects and a sensitivity margin of 0.0001m for numerical stability.

Setting configuration paramters on the command line

Each (documented) configuration parameter can be set on the commandline. This is useful if you want to briefly test a setting before rendering thousands of images. For instance the Base Configuration argument dataset.image_count, which informs about how many images ABR shall render, can be set on the command line by

$ abrgen --dataset.image_count 2

Equivalently, by using the explicit command

$ blender -b -P path_to_abr_src/cli/render_dataset.py -- --dataset.image_count 2