Here’s what I’d do. Go into edit mode. Hit alt s. This will fatten up the mesh until you get a little over lap. Now separate the parts and use boooltool to boolean them together. Now us the remesh modifier set to smooth. Adjust it to a decent density and apply remesh. Now (in edit mode) use randomize command. (Search f3 randomize). Adjust the randomize to taste, Now add a subdivision surface modifier to smooth things out.
By rendering. Use an orthographic camera in top-down view. Use a plain emission shader on the planks. Feed z-coordinate (or Camera Data->View z-depth) into emission strength (after appropriately scaling and shifting the value with math nodes).
this doesn’t feel right. shouldn’t the darker areas show on the lower positioned planks (in z) and the whiter areas on the higher positioned planks, more or less? (the result image is also upside-down btw - i think)
does this seems good enough? next is the result with the plane and displace modifier. ( i had to stretch the heightmap image later on, to be 2k x 2k, as that’s what i set the camera to be, and the planks are not 2k x 2k)
a couple more images. towards the middle and right of the plane there’s still a noticeable crease (barely noticeable with the texture tho) but towards the left of the plane, the creases appear to be less accentuated and looking ok)
The node setup should work as such. But you have little contrast in the height map (not a problem for the modifier with a 32 bit float image, but difficult to checking for correctness by looking at it). This can be tweaked better with the add/multiple values.
What I just now realized is that the planks are not aligned to the xy-plane. Should also be okay, but the precision of 8 bit RGB probably does not suffice then. Could be the reason for the waves. You certainly should use 32 bit floats for the image.
The curvature of the plane I guess is the result of a mismatch of color spaces between the saved image and the settings of the image texture on the modifier. This should also go away with a 32 bit float image.
the plane is still wavy, and a bit curved, but the creases where completly gone and it’s starting to look much better.
in this image the plane was removed of the absurd amount of subdivisions it had - i wanted to see if i could smooth the waves by having less geometry - nope. i might need to do something else.
question 1 : is the wavy because of the noticeable patterns in the heightmap image, as seen below?
question 2: how would i get rid of these noticeable patterns? with a 32 bit float image? how do i now save the heightmap render image, so the image usess a 32-bit float? save it as .exr?