Master's Thesis - Studierstube Augmented Reality Project - Graz ...

5.2 iMEDgine extensions
5.2.2.2 View Parameter Node
This node represents an essential interface to the iMEDgine framework, so it is described
separately in this section. Values are set after loading a flow dataset, so for a new view
only a reference to this node has to be passed. This node can even be exported in a
later described xml-format. Consequently, it is possible to restore a former workspace
completely for each view, see section 5.2.3.1. The available parameters are listed and
described below.
• SoSFInt32 view_type: Indicates the (iMEDgine) type of view. For example a
scripting view is associated with ”10”. (These numbers are internal mapped to
iMEDgine enum values).
• SoSFVec3f cam_position, SoSFRotation cam_rotation,
SoSFFloat cam_focal_distance: stores the position, rotation and distance from
the origin of the scene to the camera. These values are necessary to store a current
perspective.
• SoMFInt32 manipulator_positions: a list of positions for certain seed regions.
...
• SoSFInt32 time_position, SoSFInt32 num_volumes: stores current temporal
position and the overall available number of volumes.
• SoSFString primary_dataset_path, SoSFString primary_dataset_key: restoring
a former used dataset in the case of loading a view configuration require these
values. The key value equals the file name of the 4DFlow Toolbox master file.
• SoMFFloat color_mapping_texture, SoSFImage color_mapping_image,
SoMFVec4f gradient_editor_points, SoMFFloat gradient_points: are all necessary
parameter for color mapping: the 1D gradient texture, an image for convenience
and all parameter to restore the gradient editor.
• SoSFString field_path: is the path to the original used field data. This is only
needed for reloading a viewer configuration.
• SoSFDataset field_data: the interface to the raw velocity field data. The field
SoSFDataset was developed to provide the data both as SoMFFloat and as reference
to shallows GPGPU textures if they once have been generated. Storing the
references in this node is necessary and efficient because otherwise the velocity
field textures would have to be reassembled with each new view or visualization.
The SoMFFloat field on the other hand can be accessed by Cash-Flow virtual
arrays and further libraries directly. Since each view only gets a shallow copy of
the data and this node, memory requirements are optimized.
• SoSFVec3s field_dimensions: a 3D vector, storing the field’s width, height and
depth.
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