VIEW OPTIONS SHRINK [Type] [Control]

                  

This command applies a shrink factor to, and then displays all the elements in the current subset of the finite element model. It can also be used to specify different shrink factors for use with the geometry and the mesh in FEMGEN. If no shrink factor is specified a default of 0.8 is applied. If a shrink factor is specified then this becomes the current default value. A shrink factor specified as less than 0.1 will be taken as 0.1.

The picture produced is dependent on the current view mode (see `VIEW' command). Thus if VIEW EDGES is current each edge is shrunk about its centre; if VIEW FACES then each face will be shrunk, and for all other view modes the element is shrunk about its centroid.

Note that the Type parameter applies to FEMGEN only.

Type Comments

GEOMETRY Applies the shrink to the geometry only

MESH Applies the shrink to the mesh only. If type is not given then the shrink is applied to the mesh.

Control Comments

[FACTOR] Factor Specifies a shrink factor

OFF Return to unshrunken view

 

Figure 2.135: Hidden line with shrunken elements

Notes:

1.

Disadvantages in using a shrink factor with VIEW HIDDEN
If a shrink factor is used when viewing a model, normally more faces of the model will become visible. The effect of this is to increase the time taken to produce a hidden view. If the shrink factor is applied in FEMGEN , parts which were displayed as mesh will be redisplayed with the element lines shrunken about the element centroid, as in FEMVIEW.. Parts which were displayed as geometry will be redisplayed with the geometry shrunken about the centroid of the geometric part. In general, the program will take the least time to display an unshrunken picture, there will be a small time penalty for displaying shrunken geometry and a larger time penalty for displaying shrunken mesh.

Applying a large shrink factor to a very curved and narrow body can sometimes produce a confusing picture because some element faces on the body are not drawn. This occurs if the body is so curved and so narrow that when the shrink factor is applied, the body centroid now lies outside the shrunken body. If this does occur, the user is advised to use a smaller shrink factor or break the body down into smaller and less curved bodies.

Examples:

1.

VIEW OPTIONS SHRINK

The elements are shrunk with a factor of .8 .

2.

VIEW OPTIONS SHRINK FACTOR 0.5

The elements are shrunk with a factor of .5 .

3.

VIEW OPTIONS SHRINK OFF

The elements are restored to their normal size.

4.

VIEW OPTIONS SHRINK GEOMETRY .6

The geometry is shrunk with a factor of .6 .