world scale strategy fix

[brnkhy]

change world scale strategy to not include latitude compensation as it's unnecessary in this mode.

latitude compensation is necessary for fixed size tiles where we forces tiles to a fixed value. World scale ar isn't doing any scaling so should be able to use raw height data without any post-scaling.

Closes #1378

@atripathi-mb @jordy-isaac

[abhishektrip]

@brnkhy I don't think this is the right solution. Since Mercator tiles compress distance differently at varying latitudes, the compensation is necessary. However, the scaling applied to the y-axis seems to be the problem.

mapbox-unity-sdk/sdkproject/Assets/Mapbox/Unity/MeshGeneration/Data/UnityTile.cs

Line 194 in dd595b4

gameObject.transform.localScale = new Vector3(scaleFactor, scaleFactor, scaleFactor);

This scaling needs to be applied ( to y-axis) for custom Unity Tile but not for World Scale.

[asmccormick]

Thanks for all of your help! @atripathi-mb You're right -- we cannot apply the new scale factor across X, Y, and Z equally -- this will solve one axis, but it will distort the others. We must apply a new scale factor to either the horizontal or the vertical, not both.

Here's my latest solution:

1. use World Scale with 16x zoom -- this will build maps with very accurate horizontal distances. One Unity unit equals one meter.
2. calculate vertical scale factor based upon latitude:
   float verticalScale = 1 / Mathf.Cos(Mathf.Deg2Rad * (float)AbstractMapScript.CenterLatitudeLongitude.x);
3. apply verticalScale to both the terrain and the buildings.

I have a problem in Step 3. It's easy to change Terrain > Exaggeration Factor:
AbstractMapScript.Terrain.SetExaggerationFactor(verticalScale);
But I can't find a method to change Features > Buildings > Modeling > Scale Factor.

Does such a method exist?

[supergra]

In case someone gets stuck on this, go look at the fix @asmccormick posted on #1378 a few days later.