Shader Behavior Different In Editor and Debug

Help
,
1

Godot Version

4.4

Question

I’m trying to setup my tree sprite to briefly shake on-hit with an axe. I want the tree to shake more on the top than the bottom. I’m using a shader to do this, and my shader code looks like:

shader_type canvas_item;

uniform float shake_intensity = 0.0;
uniform float shake_speed = 20.0;

void vertex() {
	
	if (VERTEX.y < 0.0) {
		VERTEX.x += sin(TIME * shake_speed + VERTEX.y) * shake_intensity;
	}
}

This looks GREAT in the editor, but when I test my scene with the tree sprite in it, only 2/3 of my tree shakes. It’s like there’s an invisible line just above my bottom set of leaves, and I’m pivoting around that axis. Why would I only see this when testing and not in the editor – what am I missing?

2

Hi,

I could be wrong here, but I believe you want to use the vertex world position (at least it’s worth a try).
As in the docs:

shader_type canvas_item;
render_mode skip_vertex_transform;

void vertex() {

    VERTEX = (MODEL_MATRIX * vec4(VERTEX, 0.0, 1.0)).xy;
}

Let me know if that works. If not, could you attach some images to show the issue?

3

Thanks for the docs link – was a good read!

I tried a few different variations in my shader code using the newly defined VERTEX you have above but always landed with the same problem. It manifests like this:

In the Editor:

In my running scene:

4

I figured it out! In my Project Settings > Stretch > Mode:

  • It was set to viewport

Changing to canvas_items fixed things right up.

5

Ahh thank you so much. I am doing the same tutorial and my trees were bugging out so badly. This made the shader apply so much more consistently. No weird half shakes depending on where I hit the tree, pixel glitches, etc. :folded_hands: