Hi,
I would like to first express my gratitude towards TokisanGames for creating Terrain3D. It is amazing what you guys have done and I hope you continue to do wonders.

I am working on a terrain mapping algorithm using image data, and I am using the terrain maps that I sculpt in Godot using Terrain3D to validate the results from by algorithm. For this I need to extract the height map of the sculpted region. Starting with a simple case, I drew the following terrain.

After looking at your documentation, I wrote the following script to save the height map for this region, and attached it to the Terrain3D node.

extends Terrain3D

# Called when the node enters the scene tree for the first time.
func _ready() -> void:
	var region_res = load("res://resources/terrain3d_00_00.res")
	region_res.calc_height_range()
	var hmap = region_res.get_map(0)
	if hmap == null:
		print('Failed to import resource')
	else:
		hmap.save_png("res://maps/hmap1.png")
		print('Saved!')

# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta: float) -> void:
	pass

The image saved looked like this.

Next, when I simply tried to plot this height map image in python using matplotlib after normalizing the pixel values (between 0,1), I obtained the following plot.

This did not resemble the shape of the terrain I have sculpted in Godot. I was unable to understand why this happened and I couldn't debug it. Can you please tell me if my approach has any mistake or where I went wrong, since I am still new to Godot as well as Terrain3D? Can you please let me know how to debug this?

Please let me know if I need to provide any more information in this regard.