Forum members keep posting screen shots of wonderful creations, but I still seem unable to solve an apparently simple problem: putting a roof on top of a building.
First of all, at least in my country (Italy), roof slopes average around 20° (raging approx. from 16° to 25°); this is way below the 45° slope easily obtainable with blocks. For a simple, rectangular building, I tried both the 4-side roof and the 2-side roof solution using wood planks, but I could achieve neither. The discussion below assumes 1 block is 50cm.
The 2-side roof in itself is easy to build with planks to whichever slope one likes. The problem is to fill the triangular 'hole' remaining between the roof and the building walls at the sides. The top angle of this triangle is 180° - 20° * 2 = 140° (for a 20° roof slope) and the less acute triangular plank one can make has a 90° top angle (<= triangle 1 block wide and 1/2 block high); more than 90° seems impossible (yes, I know that triangle plank is not officially supported, but what anybody else does to achieve this?).
The 4-side roof, in principle, could be made by tessellating each side with triangular planks (alternating one row of up-pointed triangles and one row of down-pointed triangles, as triangles can only be isosceles and cannot be wider than 2 blocks = 1 m).
The shortest triangle is 1 block high (= 0.5 m) and, of course, would give a roof slope of 0°, which is not good! The minimum height increment is at 0.55 m, which gives a roof slope of 24.62°, almost at the maximum, but still acceptable. However, this raises two problems:
1) the nearest plank slope achievable by plank rotation is 25°, which seems quite near, but over the full height of the roof it accumulates to a noticeable gap between the edges of the roof sides.
2) the X, Y and Z displacements from one row to the next are irrational and I found it impossible to place the second row decently contiguous with the first (and the third with the second and so on): the result looks more like a casual patchwork than a reasonable roof.
Am I forgetting / overlooking something? How do other users approach this issue?
Thanks, M.