classes/class_shadermaterial

[giscus[bot]]

classes/class_shadermaterial

Inherits: Material< Resource< RefCounted< Object A material defined by a custom Shader program and the values of its shader parameters. Description: A material that uses a custom Shader program to ...

https://docs.godotengine.org/en/stable/classes/class_shadermaterial.html

[NullPainter2]

param doesn't support array access syntax from OpenGL's glGetUniformLocation. So "my_uniform[0]" will not work.

To set array You have to use just uniform name and pass collection using array

Godot.Collections.Array

https://docs.godotengine.org/en/stable/classes/class_array.html#array

[TheMrStraffy]

I don't know if somewhere this has been pointed out, but it drove me crazy when i tried to access and set/modify a shader parameter because it wasn't coming out in my editor when it was listing the usable methods on "sprite_2d.material."

So i went for "sprite_2d.set_instance_shader_parameter("property", value)" because it was the first thing showing up, but that didn't work either because in the script.gdshader the variable needs to be "instance uniform nameVariable" otherwise it wont' be accessible.

Just putting it out there, if you have the shader_material.gdshader written like this:

uniform float green : hint_range(0.0, 1.0);

void fragment() {
	COLOR = texture(TEXTURE, UV);
	COLOR.g = green;
}

injected into the shader_material.tres and the shader_material.tres into the sprite_2d then:
sprite_2d.material.set_shader_parameter("green", 1.0)

Otherwise you can access and modify the property like this:
sprite_2d.set_instance_shader_parameter("green", 1.0)
ONLY if the variable in the .gdshader is written like this:
instance uniform float green : hint_range(0.0, 1.0);

[minifigmaster125]

Thank you, this was incredibly confusing. Not sure why set_instance_shader_parameter isn't on the Material class.

[Calinou]

Not sure why set_instance_shader_parameter isn't on the Material class.

set_instance_shader_parameter() is specifically for per-instance parameters, which means it's on the MeshInstance node as opposed as the Material resource. Resources can be shared across several nodes, while nodes are always unique by design (even if they may use shared resources).

You should only use per-instance shader uniforms when it's actually needed, as there is a stricter size limit to them. In comparison, standard shader uniforms also have a limit, but it's much higher and almost never reached in practice.

set_shader_parameter() is part of ShaderMaterial and not Material, because Material is the base class of BaseMaterial3D which doesn't expose uniforms you can adjust directly.