D3PLOT 22.1

LIMITING_VALUES... Limiting What is Contoured by Value Range

LIMITING_VALUES... Limiting what is contoured by value range

By default all elements are contoured, regardless of whether or not they lie within the max & min range of the contour bands specified. Elements lying outside these bands are given the highest or lowest contour band colour as appropriate.

In some cases you may wish to contour only those elements which lie within a restricted range of values, and to omit (or draw only in outline) those outside this range. This can be done with the LIMITING_VALUES option.

This figure shows the control panel for the LIMITING_VALUES options.

When the Limiting switch is off, (default), the other options in this panel are greyed out.

Lowerbound value is the value below which data are not contoured.
Upperbound value is the value above which data are not contoured.
Action for excluded defines what happens to excluded elements, see below.

You need to consider what action is to be taken with elements that are not contoured. There are three options, which it is convenient to take in reverse order.

limiting values 1

The Auto bands range options determine how Limiting Values interact with automatic contour bands when limiting is active:

Temp max + min Is used when the short cut "click on a contour band" option in Clicking on the contour bar to set levels has been used. This temporarily sets contouring to enforced max/min values, which conflicts with this mode, and should not be set manually.
Full data range If automatic contour bands are in use then they will adjust themselves to the full range of data available, ignoring the lower and upperbound values set here. Therefore the contour band boundaries will not change as the upper and lowerbound values are changed here.
Clamp to limits Restricts automatic contour bands to the limits set here, changing as they change. Therefore whatever is drawn on the plot will exploit the full range of contour bands and colours available, making this suitable if you want the maximum colour and band discrimination for what is drawn.

The following three examples are a mold filling (fluids) analysis in which a plate comprised of solid elements is filled from below. They show the effects of the three Action for excluded options, in particular note how this affects the display of internal structure:

This figure uses DRAW_IN_BLACK for elements that lie outside the limiting values. (Black is reproduced as white on a hardcopy as here.)

Here we are plotting "void fraction", ie %age fullness of fluid, and only values in the range 0.8 to 1.0 (ie 80% full or more) are shown.

It is clear that no internal structure is visible since elements on the outside faces, which are not full, obscure it.

limiting values 2

This figure uses OUTLINE for elements that lie outside the limiting values.

Only the outline of elements which are out of range is drawn, so that they do not obscure structure behind them.

In this example free edge display ([DISPLAY_ OPTIONS] FREE_EDGE) has also been used to remove clutter of excess mesh.


limiting values 3

This figure uses OMIT for elements that lie outside the limiting values.

Now only those elements that are within the specified limits are drawn at all, those outside them are effectively blanked from the display.

limiting values 4

The default state of the LIMITING_VALUES switch is off, so that none of these settings apply.

When turned on it will apply to any data plotting mode, but clearly the OUTLINE and DRAW_ IN_BLACK options for excluded elements are only meaningful for 2D and 3D elements.


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