Wireframe Modeling Modeling Using Wireframes

Other pages in this series: 1 | 2 | 3 | 4 | 5 | 6 | 7

The most precise way to define a geological boundary in three-dimensions is with a wireframed surface or wireframed solid. Both are essentially the same except that wireframe solids enclose a volume while a wireframe surface is normally open. They may also differ in the techniques employed to create them. The use of wireframes, while giving more precision than perimeters, will require a thorough knowledge of how the deposit behaves in three-dimensions. The starting point for solid wireframe modeling is usually a series of perimeters outlining the geology. These perimeters need not be planar and may lie at any orientation. They must not however overlap in three dimensions with themselves (forming a knot or 'twisted bowtie' shape) or with adjacent perimeters.

Wireframe Concepts

Wireframes are defined on the basis of :

• GROUP: a GROUP can consist of one or more distinct wireframes which have either the same surface identifier, or different surface identifier.
• SURFACE: an individual wireframe SURFACE can be selected from within aGROUP of wireframes. This surface can be either a DTM or a solid wireframe.
• LINK: each wireframe surface consists of a number of individual links.

This classification of wireframe GROUP and SURFACE provides a means by which wireframes can be identified for operations such as combining and verifying wireframes which will be outlined later. It also provides greater control when using the ‘erase’ commands. You can erase GROUPs, SURFACEs, LINKs and individual triangles. The wireframe group, surface and link identifiers are stored in the wireframe point and triangle files as field GROUP, SURFACE and LINK respectively. These values are assigned internally by the system. It is possible to select wireframe data based on group and/or surface number.