There are 2 heightmaps, a terrain height map and a territory height map.
A heightmap is an image in grayscale, that defines how high the map should be for every pixel.
A black value indicates no height at all, while white indicates maximum height.
All grey shades in between black and white are used to indicate height values between 0 and the max.
The max height can be set in the map designer screen.
To make them, I used the following (but this was a long time ago):
1. Create an extra layer in inkscape underneath your map
2. Make a big rectangle thats the size of the map, and set its background fill to black (000000ff)
... a) Don't forget to check the border color from this rectangle (set border color transparent of black)
3. Draw your height on the black map
... a) This is easiest using HSL color mode, with H=0, S=0, L=height value, A=100
... b) You can use the gradient tool to make smooth hills
... c) You can set the opacity of your normal map layers to 50% or so, that way you can see where your hills are in relation to your map
... d. You probably want to lock all your normal map layers so you dont accidently draw over the wrong layer or move an path
4. Once your height map is done, export your height map as png (File > Export)
... a) Select all objects in your height map layer
... b) Make sure to tick the "Export selection only" box
You obviously don't want to upload this height map layer to WZ, so when you want to create a version of your map to upload, use File > Save A Copy (and use Plain SVG instead of Inkscape SVG, since its a smaller file size), and delete the height map layer and all other unwanted objects from that copy. You can then upload the copy to WZ.
EDIT: Come join the map making discord, thats easier than using the forums and you also get much faster replies:
https://discord.gg/zuUhzfS9
Edited 11/4/2024 09:00:30