Compatibility with OGRE_RESOURCEMANAGER_STRICT

[kPYKx7Ddw4n1aIKZ]

I did some changes to solve #11. It works but I still would want to change 6fc5be6842bde87243065e8bdd0b72f491c982dc because it is a workaround/hack. The terrain itself uses the resource group TerrainResources but the layer textures are using the resource groups TerrainGroupDiffuseSpecular/TerrainGroupNormalHeight. When trying to find them, the resource group of the terrain is used, which does not work with the layer textures in different groups.

One could either move all the textures into the TerrainResources group or add the resource groups to the layer textures in the Terrain class instead.

However, I don't know which one is the most convenient way here.

[paroj]

One could either move all the textures into the TerrainResources group

this is the preferred solution as resource groups are meant for resources that should be loaded & unloaded as a unit. This is clearly the case with the terrain geometry and the terrain textures.

[paroj]

:+1: