Modifying perlin noise with preset values
Hi.
I was wondering if it's possible to set custom values on 2D-map before generating perlin noise, so that the noise would take said values into an account when generating the noise.
Simplified example: let's say I'm trying to generate a 100 x 100 sized height map with height values varying from -1 to 1 and where all pixels before y-value of 50 would have a value of 0. If I set the height values to 0 by hand and then generate the noise after that, it creates a grey box to the half way of the map and after that generates the noise normally.
Is it possible to set half of the values by hand, and then generate the noise so that it would take the preset values into account and would continue setting the values accordingly (seamessly)?
My goal is to first draw a road with bezier and after that generate random landscape around that. The reason I want to create the road first and not after generating the noise is that I want the possibility to use different perlin values on either side of the road.
I hope that made any sense :D
Thanks!