Perlin Noise influence
Blitz3D Forums/Blitz3D Programming/Perlin Noise influence
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| Anyone know how to influence perlin noise generation? I have a 400x400 black and white picture where white = land and black = water. I want this to influence a 1024x1024 map that is generated by a perlin noise formula (i don't pretend to understand the thing completely ...) I was thinking I could check and store the pixel colors for each pixel on the lowres map, then somehow transfer them over to the potential values that come from the perlin generation. Get any of that? If you do, please help me out! Thanks. |
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| hmm. this IS a hard one. I think it would be pretty hard to inffluence the algo itself. so, I think some post or preproccessig would be in order. One method would be to simply scale up your 400x400 to 1024 with smoothing. white pixels would be grey 128,128,128. the perlin mapping would generate values from 0 to 128 and add that directly to the thing produced before. Of course, to make it differentiate less, lower the color value of land, and make the perlin mapping generate from 0 to (256-land value). |
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| Why do you want to do this? It seems to me that one would not want their water surface to be part of the same mesh as the land. Therefore I can only surmise that you would be doing this because you would want the areas underwater to have a different topology to those above water. And that seems uneccessary to me. Then again perhaps what you really want is for those areas which have water to have indentations. If that is the case, then all you really need to do is multiply the water map with the perlin noise map. If the water part if darker than the land, then those areas will be reduced in height, creating valleys for the water to be in. This would work best if you first blurred the water map slightly. |
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| Wow, thanks! That did the trick. Swift, it's 2d only, not 3d but I got what you were saying! Thanks for the concern. Btw, It's also because I made a small little pre-mapping program where even the most simple-minded could rough out a plot of land in grey/black that would be translated into a pretty 2d landscape, ready to be prettied further with "cities" and "trees" (all 2d too) |
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