External Objects

Jim can load objects into the 3-D display if they are defined externally in files that describe the shape as a set of polygons. Jim can load objects in these file formats:

Various tools in Jim can create VRML object files, including the Brain Finder and the the Fuzzy Connector. After a VRML file has been created on disk, it can then be loaded into the 3-D display.

To add geometry defined in one of the formats above, files, select Load from 3D file ... from the File menu of the 3-D Viewer: Button to select a 3D geometry file

A dialog will now appear, for you to select the 3D geometry file.

3d_vrml_dialog

Select the geometry file that you want to display. Either click on the Select obj file button button, or type in the path to the geometry file name (and press return).

Note: geometry files tend to be quite large and can take a long time to load.

If the geometry file contain suitable geometry that can be displayed by Jim, then it will now appear in the 3-D display.
Note: Not all geometry files will contain geometry that can be displayed, since they can describe other 3-D elements, such as interactions and movement. If the VRML file does not contain displayable geometric objects, Jim will pop up an error message.

You can change the appearance of the geometric objects displayed by changing the following settings:

  • Opacity. The opacity has a value between 0 (completely transparent) and 1 (completely opaque). Change the opacity using the opacity slider.

    The opacity slider in the 3d display

  • Colour. The default colour with which the surface or outlines are rendered is grey. To change the colour, click on the Button to change the colour of objects in the 3-D display button and select the new colour from the colour chooser that will pop up.
    Note: VRML allows the colours of individual geometry nodes (vertices) to be specified, whilst setting the colour will set the colour off all nodes the same. If you change the colour of a VRML object in this way, the per-vertex colours will be lost and you would need to reload the VRML file to get them back. For example, the VRML brain surface produced by the Brain Finder tool has the colours of the triangular mesh set to different shades of grey according to the depth of the sulci.

  • Surface shininess. The surface shininess has a value between 1 and 128. Change the shininess using the Spinner to set the shininess of objects in the 3-D display spinner.

  • Render mode. Surface meshes loaded from a VRML file can be rendered as:

    • A solid surface. Select a render mode of "Fill".
    • A mesh of lines connecting the vertex points. Select a render mode of "Wire frame".
    • A cloud of vertex points. Select a render mode of "Points".

The pictures below are a VRML brain surface extracted by the Brain Finder, and a Wavefront OBJ file created externally.

|Button to finish with the 3D object dialog|3d object loaded from a Wavefront OBJ file|

If you click the Done button, the objects will be removed from the 3-D viewer.