grunk/src/shaders/gunk/gunk.gdshader

// -*- mode: glsl -*-
shader_type spatial;
render_mode depth_prepass_alpha;

#include "common.gdshaderinc"

group_uniforms jitter;
uniform mediump float jitter_magnitude = 0.0;
uniform lowp float jitter_time_scale = 0.1;

uniform highp sampler3D jitter_noise;

group_uniforms inflation;
uniform highp float vertex_inflation = 0.0;
uniform highp float inflation_pixellation = 10.0;


void vertex() {
	float mixer = VERTEX.x + 0.553 * VERTEX.z + 1.618 * VERTEX.y;
	float local_time = floor(TIME * jitter_time_scale * time_pixellation) / time_pixellation;
	float sample = texture(jitter_noise, vec3(cos(mixer), sin(mixer), local_time)).r;
	float inflation = floor(vertex_inflation * inflation_pixellation) / inflation_pixellation;
	float jitter = jitter_magnitude * (sample - 0.5 + inflation);
	VERTEX *= 1.0 + jitter;
}

void fragment() {
	vec3 uvt = scale_uvt(UV, TIME);
	float value = sample_noise(uvt);
	ALBEDO = base_albedo(UV, value);
	ROUGHNESS = base_roughness(value);
	EMISSION = base_emission(UV, value);
	SPECULAR = base_specular();

    vec3 nmap = sobel_convolution(UV, uvt);
	NORMAL_MAP = nmap / 2.0 + 0.5;

	// add fresnel
	vec3 world_normal = mat3(TANGENT, BINORMAL, NORMAL) * nmap;
	EMISSION += rim_glow(
		world_normal,
		VIEW,
		fresnel_gradient,
		fresnel_color,
		fresnel_power,
		fresnel_intensity
	);

	// add iridescence
	ALBEDO += rim_glow(
		world_normal,
		VIEW,
		iridescence_gradient,
		iridescence_color,
		iridescence_power,
		iridescence_intensity
	);
}