Trelis 16.5 User Documentation

**Applies to**: Surfaces

**Summary**: Places triangle
elements at some vertices, and map meshes the remaining surface.

**Syntax**:

Surface <range> Scheme Trimap

**Related Commands**:

Surface <range> Vertex <range> Type {Triangle|Notriangle}

**Discussion**:

Some surfaces contain bounding curves which meet at a very acute angle. Meshing these surfaces with an all-quadrilateral mesh will result in a very skewed quad to resolve that angle. In some cases, this is a worse result than simply placing a triangular element to resolve that angle. This scheme resolves this situation by placing a triangular element in these tight corners, and filling the remainder of the surface with a mapped mesh.

The algorithm can automatically compute whether a triangular element is necessary, along with where to place that element. To override the choice of where triangular elements are used, the following command can be issued:

Surface <range> Vertex <range> Type {Triangle|Notriangle}