Iterative parallax mapping

More lightweight than parallax occlussion mapping, better looking than basic parallax.

Shader code
shader_type spatial;
render_mode blend_mix,depth_draw_opaque,cull_back,diffuse_burley,specular_schlick_ggx;

uniform vec4 albedo : source_color;
uniform sampler2D texture_albedo : source_color,filter_linear_mipmap,repeat_enable;
uniform float point_size : hint_range(0,128);
uniform sampler2D texture_orm : hint_roughness_g,filter_linear_mipmap,repeat_enable;
uniform float ao_light_affect : hint_range(0.0, 1.0, 0.01);
uniform sampler2D texture_normal : hint_roughness_normal,filter_linear_mipmap,repeat_enable;
uniform float normal_scale : hint_range(-16,16);
uniform float heightmap_scale;
uniform int height_iters_max : hint_range(1, 30, 1) = 10;
uniform int height_iters_min : hint_range(1, 30, 1) = 4;
uniform vec2 heightmap_flip;
uniform vec3 uv1_scale;
uniform vec3 uv1_offset;
uniform vec3 uv2_scale;
uniform vec3 uv2_offset;

void vertex() {
	UV=UV*uv1_scale.xy+uv1_offset.xy;
}

void fragment() {
	vec2 base_uv = UV; //Parallax code starts here
	{
		vec3 view_dir = normalize(normalize(-VERTEX)*mat3(TANGENT*heightmap_flip.x,-BINORMAL*heightmap_flip.y,NORMAL));
		
		float num_layers = mix(float(height_iters_max), float(height_iters_min), abs(dot(vec3(0.0, 0.0, 1.0), view_dir))/2. ); //Distance lod
		num_layers = round(num_layers/3.)*3.; //Layers stepped every 3
		
		for (float i = 0.; i < num_layers; i++){
			float h = (texture(texture_orm, base_uv).a - 0.5); //Uses alpha channel of ORM texture
			h *= heightmap_scale/num_layers;
			h -= (1./(i+1.))*(1./num_layers);
			h = clamp(h, -0.5, 0.5);
			h -= 0.5/num_layers;
			
			vec2 view = view_dir.xy;
			view *= 0.01;
			view *= h;
			
			base_uv += view;
		}
	}
	
	//Material stuff
	vec4 albedo_tex = texture(texture_albedo,base_uv);
	ALBEDO = albedo.rgb * albedo_tex.rgb;
	vec4 orm_tex = texture(texture_orm,base_uv);
	ROUGHNESS = orm_tex.g;
	METALLIC = orm_tex.b;
	NORMAL_MAP = texture(texture_normal,base_uv).rgb;
	NORMAL_MAP_DEPTH = normal_scale;
	AO = orm_tex.r;
	AO_LIGHT_AFFECT = ao_light_affect;
}
Tags
material, parallax
The shader code and all code snippets in this post are under CC0 license and can be used freely without the author's permission. Images and videos, and assets depicted in those, do not fall under this license. For more info, see our License terms.

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Starfield with Parallax Scrolling Effect

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Unhinged Dev
8 months ago

amazing stuff man!

moonlightart
moonlightart
6 months ago

Hi!

This looks awesome, but for some reason the parallax effect is not working for me.
I have tried different “Heightmap scale” values and used this texture:
https://3dtextures.me/2021/04/22/rocks-hexagons-002/

Do you have a sample project that shows this shader in action?
It is precisely what I need and I can’t figure out why it is not working…

Any answer would be appreciated! 🙂