[4.3&4.4-dev7] Light: Gdshader Normal assignment seems wrong.

[RickyYCheng]

Tested versions

Godot v4.3.stable.mono - Windows 10.0.22631 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3050 Laptop GPU (NVIDIA; 32.0.15.6094) - AMD Ryzen 7 5800U with Radeon Graphics (16 Threads)
Godot v4.4.dev7.mono - Windows 11 (build 22631) - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3050 Laptop GPU (NVIDIA; 32.0.15.6094) - AMD Ryzen 7 5800U with Radeon Graphics (16 threads)

System information

Windows 10.0.22631 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3050 Laptop GPU (NVIDIA; 32.0.15.6094) - AMD Ryzen 7 5800U with Radeon Graphics (16 Threads)

Issue description

Chech this image (dir light, 45 deg, .25 height):

Left: gdshader with Canvas Texture (with albedo and normal)
Right: Canvas Texture (with albedo and normal) without gdshader

shader_type canvas_item;

uniform sampler2D albedo : filter_nearest;
uniform sampler2D normal : filter_nearest; // add hint_normal

void fragment() {
	COLOR = texture(albedo, UV);
	NORMAL = texture(normal, UV).rgb;
}

Steps to reproduce

Check MRP.

Minimal reproduction project (MRP)

NormalTest.zip

[clayjohn]

This isn't a problem in Godot. You are calculating your normal incorrectly in the shader. You need to assign normal map values to NORMAL_MAP, not to NORMAL. Correcting that in your shader fixes it

There is a section in the docs that explains the correct way of handling normals in shaders in detail https://docs.godotengine.org/en/latest/tutorials/shaders/shader_reference/canvas_item_shader.html#normal