@Big Frank - there are a couple philosophies about the use of shadows in maps. While the majority of the time, I try to keep a consistency of the shadow - usually as a drop shadow dropping down and to the right. However, its a common practice that when deliniating walls (like the walls of the cave in the area you point out) to use a halo shadow to distinctualize the difference between floor and wall. Game-wise its important to determine the floor space where combats occur. Using a drop shadow means that on the opposite side of an object with shadow features, has no shadow. So it can be difficult to acertain where the floor ends and the wall begins. For combat situations in-game, having no shadow to determine where the floorspace ends can be problematic.

So artistically, as a rendition of a given mapped area, the lack of consistency in the depiction of shadows might diminish the aesthetic results. However, my maps are specifically designed for use in game, rather than as an art piece. So I use consistent halo shadows on all wall structures (only), as a mechanical structure useful for game play. If I were only trying to create an art piece of a photorealistic top down view of a given piece of ground (and not as a map for game play) I would certainly keep the shadow consist throughout the entire map. Because my maps are purposely designed for game play as a priority goal, meeting the needs of gamers are more important than doing art.

For example, here is my final design of a 2-masted sailing sloop as the final step in my last map tutorial for the first guide book. Note that consistent use of drop shadows (dropping down and to the right) is used throughout, especially consistently in the top deckplan - what can be seen from above. However, in the second map that depicts the chambers under the rear poop deck, with surgeon's chamber, 1st officer and navigator quarters, galley, stairs down to the underdeck, and the captain's quarters, notice that the walls have a halo shadow - again the consistency of halo shadows on walls for the purposes of game play only.

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