General Information

• OpenGL and Windows Operating System

OziExplorer3D uses the OpenGL graphics engine for high-performance 3D graphics similar to the engine used in many of the video games. Most video card manufacturers support OpenGL, but to get the best performance from your computer it is important to make sure you have the most recent drivers. Hardware acceleration of OpenGL requires special drivers which take advantage of the graphics hardware in the system.

• What if I only have a basic graphics card and my maps rotate slowly

If your system does not have a graphics card with hardware acceleration, the software will perform slowly. The reason for this is that although most Windows users will have access to a software implementation of OpenGL, it uses the CPU (instead of a dedicated graphics card) to render 3D graphics. Windows 95B (OSR2/2.1), Windows 98 and Windows NT 4.0 all ship with Microsoft software implementations of OpenGL.

If you select "Wire Frame Rotate" in OziExplorer3D configuration, the software will operate better on your system when you drag or rotate your map. Use of smaller map sections with less vertices will improve performance.

• Will 3D graphics cards improve the performance of OziExplorer3D

Yes, if you have a graphics card with built-in opengl 3D support you will get an improved performance from one without. However, you should obtain specialist advice on which graphics best suits.

• I have DEM files which are projected in the local Grid and map datum, how can I use these.

OziExplorer has the ability to specify the grid and datum being used, see the Height Data help (bottom of the page) for information on how to do this.

• When I select the "whole map" my computer is very slow.

1. Try selecting a smaller section of the map, some computer systems will not be able to handle selection of the whole map, particularly if the map is large.

2. Reduce the number of vertices. Some computer systems will slow down if you have 10,000 or more vertices.

3. If you select "Wire Frame Rotate" in OziExplorer3D configuration, the software will operate better on your system when you drag or rotate your map.

• My track elevation does not correspond with the map elevation pattern (shape).

1. The height datum of the track elevation data and the DEM elevation data may be different.

2. The map will show the elevations at the accuracy of the data from the DEM file. Also the grid spacing of the data will have an effect. (eg Gtopo30 data is 1km grid spacing which will tend to smooth out the map elevation shape).

3. The track height data captured by a GPS is not accurate.

There are two elevation offsets you can make

• In OziExplorer / Elevation Configuration, you can enter an "Elevation Adjustment" value (m). This will adjust both your Track heights (from GPS) and your map elevations from your DEM files.
• In OziExplorer3D, the "Elevation Offset" on the Map Control allows you to adjust your 3D map elevation.

• Can height data captured by my GPS with a track be used to replace DEM data for my map.

If height data is downloaded with the track then it will be used in the track display. It cannot be used to replace the elevations shown from the DEM data.

• My heights do not agree with the contour lines on my map

The units (metres /feet) may not be correct, check that the units selected in OziExplorer are the same as the units the contour lines are drawn.

We have seen DEM data files with incorrect data, use the "Elevation Adjustment" in OziExplorer / Elevation Configuration to adjust the data. (Don't forget to reset the Elevation Adjustment back to zero).

• My operating system is Windows 95

  Windows 95 and Windows 95a users may download OpenGL Version 1.1 from Microsoft's website. Download it and place the files in the Windows\System directory. It should fix OpenGL problems with the Win95a Operating System.

  DO NOT run this program unless you have the original edition of Windows 95 AND you are specifically getting the error message that you are missing OpenGL32.DLL.

  Windows 95 OpenGL Update or Download Windows 95 OpenGL Update from Microsoft
   

• My map doesn't look smooth, it has ridges which should not be there

You have turned off filtering in Elevation Configuration in OziExplorer and then you have "oversampled".  In the 3D Map Control dialog in OziExplorer, the value of the grid delta (metres per grid) is a lot less than the elevation data grid. Change the grid size in pixels using the drop down box until the metres per grid value is about equal or greater than the resolution of the elevation data.

Over sampling	Normal	Under sampling

• It is taking a long time to create my 3D map

The number of vertices is too many for your computer system to process quickly. Reduce the number of vertices by increasing the "metres per pixel" or select a smaller area of the map.  Older computer systems will have difficulty processing more than approximately 10,000 vertices.