| |
|
|
Model Bounding Box
Polygonalization of infinite surfaces (planes, cylinders, and cones) requires that the surfaces be truncated. Moritz uses the Model Bounding Box to limit the surfaces. After a model is read, the bounding box is computed from the extent of surfaces and cell bounding boxes based on the cell descriptions. This box should usually be sufficient. When the geometry is being created or modified, the bounding box is increased to accommodate new and changes in surfaces, bodies, and cells. Some cases require explicit definition of the bounding box before a cell can be polygonalized, such as a cell bounded by a cone and a P, PXY, PXZ, or PYZ plane. The model bounding box can be defined on the Model Bounding Box (ModelBB) property page. An alternative method is to draw a large closed surface or body than enclosed the geometry of interest. An enclosing surface or body very much larger than the extent of the remainder of the model may cause problems and/or less than optimal polygonalization.
Transformed surfaces with large translation components can be troublesome for infinite surfaces. The untransformed surface is first polygonalized within the model bounding box. When the transformation is applied, the polygonalized surface may not intersect the model, causing the cells bounding it to not be rendered in 3D. Methods to correct the problem are under development.
 White Rock Science http://www.whiterockscience.com/wrs.html 505 672 1105 |
| |
|
|