Shader not laying on top of my sprite

Question

I'm trying to understand how to apply shaders in SpriteKit, so I made the following shader that comes from a guide with some adaptations (http://battleofbrothers.com/sirryan/understanding-shaders-in-spritekit):

void main() {
    vec4 val = texture2D(u_texture, v_tex_coord);

    if (val.a == 1.0) {
        gl_FragColor = vec4(1.0,1.0,1.0,1.0);
    } else {
        gl_FragColor = val;
    }
}

The idea of this simple shader is to translate to white every non-transparent pixel of the sprite node.

The shader works with my sprite nodes that have a single texture as their image.

The issue that I'm having is that the shader seems to be ignored when I apply it to a sprite node which comes from a multi-layered SKScene. I've tried to set the shader to every children node of the scene, but it still doesn't appear.

Any suggestions?

Sorry, I'm missing some comprehension. What do you mean by "multi-layered SKScene"? — Confused
Hi, thank you for your support. I've found the solution to my problem (which I'll post soon). Anyway, by "multi-layered SKScene" I mean that I've created a visual scene editor file (.sks), and I built my sprite inside this scene by adding different nodes for the various body parts, so that it's easy to animate the sprite with some SKActions. — gionti

gionti gionti · Accepted Answer · 2017-02-09T12:17:21

I've found a workaround to my problem.

I initially tried to apply the shader to every children node of my sprite as following:

for child in children {
    (child as! SKSpriteNode).shader = myShader
}

The code didn’t work out.

Now I use the following working code, which follows the hierarchy of my children nodes:

(self.childNode(withName: "body") as! SKSpriteNode).shader = myShader
(self.childNode(withName: "body")!.childNode(withName: "arm") as! SKSpriteNode).shader = myShader
// ...

Shader not laying on top of my sprite

1 Answers