Plot: Plot elements

The command plots selected elements within one or distinct AutoCAD layers respectively display lists. It's possible to distinguish between different kinds of plots ranging from wire frame to surface plots. In all cases curved edges are approximated by polylines where additional nodes between vertices are automatically calculated to smooth the plot. This can be suppressed when transferring elements to AutoCAD. It should be suppressed when these elements are intended to be read back (after a modification within AutoCAD) by MAKROS.

Option „Edges only“ draws the edges of the elements as wire frames. Surface elements will be drawn as closed polylines. When transferred to AutoCAD, solids of type 8x are drawn with 9 edges within one polyline, the remaining 3 vertical edges are drawn as separate polylines. All these elements can be re-read with the command Read AutoCAD.

Option „Surface mesh“ plots all selected elements as an AutoCAD mesh. This option can only be used during a graphical plot within AutoCAD. It is only implemented for elements of type 30 and 40. This kind of plotting has the advantage that all elements are corrected when moving common nodes. This isn't the case in edge plot mode where all relevant elements are drawn as separate polylines. Surface meshes can be read again as a macro or FE model. In case of a large structure it should be divided by suitable element selections into several plots.

Option „Sharp edges only“ plots edges where the angle between the normal vectors of the adjacent surfaces is larger than the given value. Only these edges and the edges with only one adjacent surface are plotted. This way it's easy to detect gaps within the structure. Solid structures are represented only by their outer surfaces. The angle must be provided in degrees.

Option „Plot of surfaces“ plots all elements in AutoCAD as a polygon mesh. Solid structures are represented only by their outer surfaces. With this kind of plot AutoCAD rendering can be used for hidden line removal or shading. Elements plotted this way cannot be read back with the command Read AutoCAD. Graphical outputs within an OpenGL window automatically suppresses hidden lines and surfaces, curved surfaces are approximated by triangles. It’s also possible to shade the structure using a specified light source.

Pressing button “Plot” starts the graphical output. By pressing button „Erase Display“ the graphics window will be erased (including all OpenGL display lists). Button „Copy“ causes a new window to be opened with a copy of the existing window so it will be possible to compare multiple views of the structure.

Following Dialog shows the available options:

Parameters

Edges only: Edges of the elements are plotted as polylines. With „No smoothing” set, no additional nodes on curved edges will be generated when transferring the elements to AutoCAD.

Shrinking: Factors < 1.0 reduces elements in size when plotted by shrinking them towards there center.

Line style: When plotting edges a line style (0-5) used for all edges can be set.

Sharp edges only: Only sharp edges of the structure are plotted. The max. angle between normal vectors must be given.

Surface mesh: Elements are plotted as AutoCAD 3D mesh (only for types 30 and 40 and option “AutoCAD”).

Plot of surfaces: The outer surface of the element structure is approximated by triangles and hidden line removal is done. An angle of sharp edges can also be given.

Shading: One or more light sources (see Light source) may be witched on to produce a shaded image.

Line width: In the input field, the width of the lines in pixels can be given.

Angle on edges: If an angle > 0 is given when using surface or shaded plots only those edges between surfaces with an angle between their normal vectors greater than this value will be plotted. This value must also be set when using “sharp edge plots”.

Culling polygon faces

Enable culling: If this option is marked culling facility of OpenGL is switched on, so that only faces with normal vector directed to the camera position (option back faces) or opposite (option front faces) are plotted.

Solid elements only: If this option is also marked, culling is only applied to faces that belong to solid elements.

Layer

Element layer: With this option set, all elements will be drawn in different layers respectively display lists. There must have been made an association of layer numbers and layer names to the elements. OpenGL graphics use one display list for each layer.

New layer: With this option set, new names for layers will be created and used when transferring the structure to AutoCAD.

Using new layer names is importing, when transferring elements to AutoCAD, because existing entities of the used layers will at first be erased. With OpenGL, using different display lists makes it possible to turn the plot of parts of the structure on and off.

Element selection

Only elements contained in the selection are plotted.

Color

From layer: The color indices associated with the layers will be used.

From element: Previously assigned element color is used.

Group IDs: The elements group ID will be used as a color index.

Index: All elements are plotted with this index.

Light source: Pressing this button, a dialog pops up where a light source can be specified.

Adjust scale

With this option set scaling and center of the image will be automatically adapted for the next plot based on the size of the current graphics window. Otherwise new scaling is only performed when changing the current element selection.

Same scale

Each time a new element selection is drawn, the reference point and scale factor are newly calculated. With this option set the old view is used instead. So different parts of the structure can be superimposed with different colors on different display lists.

Same picture

By default all display lists respectively used AutoCAD layers are erased before plotting. With this option set erasing won’t be done. When using OpenGL another display list must be specified, a previously used display list can’t be extended.

AutoCAD

With this option active selected elements are transferred to and plotted within AutoCAD. Otherwise the OpenGL graphics window is used. This option is only available after starting MAKROS from within AutoCAD.