fast_draw_settings

Fast Draw Settings

When zooming, panning and rotating, the Terrain Model shown in a Terrain Graphics Window is drawn in a simplified "fast draw" manner. The parameters in this dialog box control the way this is done.

When rendering a large grid, adjacent grid points can fall on the same pixel or on nearby pixels on the screen. This is especially likely when the view is zoomed out, so that a significant part of the entire model is on the screen at the same time. This dialog box contains parameters to control functionality that detects such situations. This functionality automatically does the rendering and drawing calculation on a coarser grid i.e. using only every second or third or fourth etc grid point.

Zoom and Rotate/Pan Parameters

These parameters define the number of the objects visible in a Terrain Graphics Window during zoom, rotate and pan operations and the speed of their movement.

Step

This parameter changes the relative step for rotate, zoom and pan operations. For example, a larger rotation step means that the view angle changes more each time the terrain is redrawn. This leads to a faster apparent "rotation" around the terrain. However there are fewer intermediate rotation positions available.

Rarefaction Level

This parameter determines the degree to which the Terrain Model is simplified when drawn in "fast draw" mode in Terrain Graphics Windows.

Fast Draw Color

This allows users to choose the color in which the terrain is drawn in "fast draw" mode.

Parameters to Speed-up Grid Rendering

These parameters control functionality used in situations when rendering can be done on a coarser grid without significantly losing detail. This functionality automatically does the rendering and drawing calculation on a coarser grid i.e. using only every second or third or fourth etc grid point.

•Use Full Grid

The full grid will be used for rendering i.e. functionality to spped-up grid rendering is turn off.

•Use Rarefied Grid

Allows users to turn on the rarefying algorithm to speed-up grid rendering.

Grid Pixel Spacing Threshold

This parameter sets a nominal threshold (minimum) pixel distance between adjacent grid points in plan view. If the actual pixel distance is less than this value, the grid is thinned until the pixel distance becomes greater than this value.

Maximum Grid Rarefy

This parameter limits the degree to which a grid will be rarefied in this functionality e.g. a value of 10 means no more than every 10th point.

•Use Thinned Grid

Allows users to turn on the thinned algorithm to speed-up grid rendering.

Maximum Spacing

This parameter sets the maximum distance between neighboring points to be used i.e. used points will never be further than this distance apart.

Angle for Detail

Angle from horizontal to use points. Smaller angle uses more points.