DISPLAY OPTIONS... Controlling Plot Parameters

DISPLAY OPTIONS... Controlling Plot Parameters

"Options" gives user control over a number of graphical features.

Most of these can be preset in the "oa_pref" file: see Graphics Setup via the "oa_pref" File. The button Save display settings saves the settings directly to the preference file.

Back faces	Determines whether or not the back (ie facing away from you) faces of 3D (solid and thick shell) elements are drawn.
Internal faces	Determines whether or not the internal faces of 3D elements are drawn. You should only use this if you need to see them, as it slows down drawing by a large factor.
LI/HI free edges	Determines whether or not the internal faces of 3D elements are drawn on LI ne and HI dden-line plots. You should only use this if you need to see them, as it slows down drawing by a large factor. The overlay on SH aded and data bearing plots is controlled in SH/CT/SI Overlay
Hatch segments	Controls how segment sets are displayed. The default is to draw a "hatched" wireframe overlay on them in order to distinguish them from ordinary 2D elements, but this can slow down graphics considerably on some platforms so it is switchable.

Historically PRIMER drew contacts using a hatched wireframe overlay but, as with segments above, this could be slow. Therefore the default has been changed to " Stippled 1x1 " which is fast, and distinguishes them visually from shells by giving them a semi-transparent appearance since every other pixel is omitted.

This is much faster than hatching, but may not be to the taste of all users, so a range of options is given as shown here. Solid shaded, hatched will give the original (slow) appearance, and Solid shaded, no hatching will give an opaque result visually indistinguishable from shells.

The default appearance can be changed in the "oa_pref" file using

primer*contact_shaded_display:  <option>

PRIMER draws ordinary (not spotweld) beams as simple lines between the 2 nodes, but when these nodes get very close together the result can be a very small point of a single pixel which is almost impossible to see.

Therefore when the distance between the 2 nodes as drawn on the screen is less than Min size the symbol is changed to "blobs" on each node of Blob dia to make them easier to see. (Both these dimensions are in screen space units.)

With True Sections switched on beams will be drawn with their explicit sections dimensions and orientation.

For beams where only Area, Ixx and Iyy properties are available then a thin-walled rectangular section that matches these properties is synthesised. This should be approximately correct, but obviously it cannot represent I beams or rectangular sections with varying wall thicknesses, but it should give a reasonable representation of beam dimensions. If you use inconsistent or impossible properties you may get some strange looking sections!

Use OPTT is now available with True Sections and will plot the beam as circular using the value of OPTT on *PART_CONTACT for diameter rather than the physical section

The true thickness of shells can be displayed in two ways as shown below:

The way that shells which are coincident with 3d element faces., "Shells on 3d Els", can also be controlled

Thin draws a shell as a single infinitely thin facet.

This is fast to draw and minimises graphics memory usage, so it is the default mode.

The two images below show exactly the same elements drawn using the two "thick" true section variants.

True flat "extrudes" each element individually, making no attempt to form a continuous surface between adjacent shells sharing a common edge.

This can be useful when trying to determine exactly what the thickness of each shell element is, as shown in this example.

However it doesn't look very nice!

True smooth extrudes as above, but attempts to join up shells at common edges to form a continuous surface.

This image shows the same elements as above, but demonstrates how edges are now joined up. It looks much better, but it is not so easy to determine the exact shape and extent of each shell.

This mode is better for presentation purposes.

The "true" shell shapes shown above take into account any variation in element thickness (eg fields T1 to T4 on *SECTION_SHELL ), and also any offsets of the neutral axis from the plane of the nodes as defined by NLOC (eg on *PART_COMPOSITE ) or by *ELEMENT_SHELL_OFFSET .

This is not the case in "thin" mode, which is always drawn on the shell's nodal plane, ignoring any offsets.

In addition if the shell is a composite then in "true" mode lines will be drawn on the sides showing the individual layer thicknesses.

The default shell display mode can be changed using the preference:

primer*shell_graphics_mode: thin  or  flat  or  smooth

The "GRATICULE" is tick marks around the edge of the plot which show the current window dimensions: useful for estimating distances on the screen (although MEASURE provides a more accurate method). For more information on the graticule see Graticule.

These sizes can be controlled via the preferences:

primer*lumped_mass_size: < size >
primer*spring_size: < size >
etc

Lumped mass symbols can be displayed in two different ways, controlled via the popup on the Masses size button.

2d square	2d square symbol. Not very attractive, but very fast to draw
3d cube	3d cube symbol. Attractive and intuitive, but much slower to draw. Models with masses at many nodes become unacceptably slow to respond to dynamic viewing commands if this display method is used.
Automatic	Uses "3d cube" symbols if there are < 10,000 mass elements in the model, otherwise "2d square". This is the default since it gives a reasonable trade-off between image quality and rendering speed.

The default lumped mass symbol display mode can be controlled by the preference

primer*lumped_mass_symbol: square|cube|automatic

Triad size  can also be controlled. Normally the size of triads are drawn according to their respective elements, but sometimes the triads are so small at the current graphics scale that the resulting triads would be very hard to see. To make these small triads visible, PRIMER supports a minimum factor and a scale factor for triads:

The minimum factor controls the minimum triad size. It can be any float value (larger than 0.0) which limits the minimum triad size according to a factor of the model size. Any triads that are smaller than the minimum triad size will increase to the minimum triad size. An approximate calculation of the minimum triad size is as follows:
Min triad size = (Triad min factor / 1000.0) * (Diagonal model length)
Note: Since the minimum triad size depends on the diagonal length of the model, different models will have different minimum triad sizes.

The scale factor will scale the size of triads by the factor specified. It can be any float value (larger than 0.0). The logic used is as follows:
Triad size = Triad scale factor * Original Triad Size

Both the minimum factor and the scale factor can be turned on/off according to the tickboxes that control them. When they are both on, the triad size will be evaluated as follows:
(1) Triad size = Triad scale factor * Original Triad Size
(2) If triad size (evaluated above) is smaller than min triad size: Triad size = Min triad size
Both factors are turned off by default. The default values for triad minimum factor and triad scale factor is 4.0 and 2.0 respectively.

• Labels
• Title & Date
• Contour Bar

The default options for all three types is Automatic. That is, PRIMER will select an appropriate font size which will vary with window size. If an explicit point size is selected, the text size will stay constant, no matter the size of the window.

If antialiasing is turned on lines will typically look slightly thicker, and lines drawn at an angle will be noticeably smoother. The example image here shows a spring symbol both without (left) and with (right) antialiasing, the effect is particularly noticeable on the curved lines.