Constant MESH_FRAGMENT_SHADER 

pub const MESH_FRAGMENT_SHADER: &str = r#"
#version 450

layout(location = 0) in vec3 v_color;
layout(location = 1) in vec3 v_normal;

layout(set = 0, binding = 0) uniform Uniforms {
    mat4 view_proj;
    mat4 model;
    vec3 light_dir;
};

layout(location = 0) out vec4 f_color;

void main() {
    float light = max(0.1, dot(normalize(v_normal), normalize(light_dir)));
    f_color = vec4(v_color * light, 1.0);
}
"#;

Fragment shader for mesh rendering