Hi,

I am trying to understand the CDB format.

I was wandering what is the best practice to define then render this type of dirt road:

Sample image

1. How should I define it in the CDB database?

2. How should I render this type of 3d road into the terrain surface without depth fights and such?

3. How do I make sure the rendering (texture, lighting and such) look the same in my product as it look in Presagis products - so my client will see the same visuals on both systems?

Cheers,

A

Hi,

1. How should I define it in the CDB database?

Such a road is a combination of vector, elevation, imagery and material datasets in CDB. For a Visual, you typically only need the elevation (TIFF), Imagery (Jpeg2000) and material. The vector (road network dataset) is used for generating all those raster datasets and to perform road following in simulation.

Note that CDB 3.2 provides a nice elevation sub-dataset (section 5.6.1.4) to facilitate the high resolution elevation needed in this case.

2. How should I render this type of 3d road into the terrain surface without depth fights and such?

If the road is part of the imagery layered on the elevation grid, you will have no depth fights.

3. How do I make sure the rendering (texture, lighting and such) look the same in my product as it look in Presagis products - so my client will see the same visuals on both systems?

If you render the data as it is in the CDB, you should get the same visual. However, CDB does not standardize the lighting model or environmental effects which may differ between rendering engines. However, using the same CDB must provide perfect correlation of features and position between all systems and this should be your focus rather than the same lighting effects.