Just to make sure, your DEM file will look right in Vue ...

The info, that 3DEM gives -  look at the image i've included
img524.imageshack.us/img524/9592/3demls5.jpg

You can see the highest point in your terrain by calling up this color scale bar (to the left in the above image) - here in this area it's 4.19 km ( roughly 4190m, the exact values you get choosing 'Modify Scale' - where another window appears showing the colors regarding to the certain heights and the exact altitude range values). You need to adjust this in Vue lowest to hightest point in comparison with your ZERO water line (ground line for example), to get the terrain looking right in the Z-value.

What else you need to know is the X and Y length of your DEM terrain.
By displaying the 'DEM Specifications' window (in the menu with 'Show DEM Specs').
Here you'll get the Longitude and Latitude range.

The above image shows -110.961 to -110.385 longitude.
Subtract 110.385 from 110.961 and you get 0.576
Multiply 0.576 x 110 km (110km is roughly 1 degree of the circumference of the earth) and you'll get 63.36 km as length in X-value.
Same calculation for the Y-value.

These are the values you'll need to input in Vue terrain size. This might be way to large scaled to work with in Vue - so down scale it by dividing it with10 or 20 for example - so you'll get like 6.3 km or 630m terrain size - to large of an area in Vue will give you trouble with eco or whatever, since it has to cover an extreme large area with plants ...