Non-tiling shingles?

[kevin miller]

What I do in a pinch is make two variants on the same thing and Mix them. With grass I'll just use the same grass twice but size it a little different and rotate it 37 degrees and mix with noise. With shingles/block I'll mix them with a tile.

 

The two shingles here are the same map actually just shifted 50% in each direction. This is not a good way to create randomness. But you can see it is passable (or better than nothing?) with very few shingles indeed.

 

The tile map is set to create tiles the same size and pattern as the source maps (48" x 36", 4 x 3) and then because it's easy I multiply by ten (480" x 360", 40 x 30). That will give a repeat, but a big one that topology, perspective, trees... will hide or minimalize. Anyway...

 

The tiles are set to white, the grout to black but of zero size. Then give the grout a % holes. "Oh," you might think, "50% for the perfect half and half mix of the two!" And you would appear to be wrong. I don't claim that what you see here is the perfect mix of the two, but it is 20% holes.

 

Tweak % holes and random seed until you get something you like.

 

Notice though, I forgot that the half tiles on the edges not only have to meet across one bitmap (which I did do) but they need to match across bitmaps. You can see a great seam running up the roof about 2/5ths in from the left which is caused by that.

 

I am sorry for resurrecting an old post but I was searching for posts on how to create a non-repeating roof shingle material and I found this post. This seams to make some sens but I do not seem to be able to translate Peter's brief instructions into anything like what he shows. I readily admit I am not a texturing expert. Could someone please help me with understanding in a little more detail what exactly Peter is doing here? Thanks! K.