Blend ORM materials (+trim sheet tutorial)
This is a simple material blending shader based on Godot’s ORM material. It blends two materials based on the mesh red channel vertex color.
I’ve created this for my “how to make trim sheet textures very fast and easily with Material Maker” video tutorial for my youtube channel (its in spanish). You can find the video tutorial and the sample project with a custom Material Maker node, on my github.
Shader code
// NOTE: Shader based on an automatically converted one from Godot Engine 4.6.1.stable's ORMMaterial3D.
shader_type spatial;
render_mode blend_mix, depth_draw_opaque, cull_back, diffuse_burley, specular_schlick_ggx;
uniform vec4 albedo_a : source_color = vec4(1.0, 1.0, 1.0, 1.0);
uniform sampler2D texture_albedo_a : source_color, filter_linear_mipmap, repeat_enable;
uniform vec4 albedo_b : source_color = vec4(1.0, 1.0, 1.0, 1.0);
uniform sampler2D texture_albedo_b : source_color, filter_linear_mipmap, repeat_enable;
uniform sampler2D texture_orm_a : hint_roughness_g, filter_linear_mipmap, repeat_enable;
uniform sampler2D texture_orm_b : hint_roughness_g, filter_linear_mipmap, repeat_enable;
uniform sampler2D texture_normal_a : hint_roughness_normal, filter_linear_mipmap, repeat_enable;
uniform float normal_scale_a : hint_range(-16.0, 16.0) = 1.0;
uniform sampler2D texture_normal_b : hint_roughness_normal, filter_linear_mipmap, repeat_enable;
uniform float normal_scale_b : hint_range(-16.0, 16.0) = 1.0;
uniform sampler2D texture_heightmap_a : hint_default_black, filter_linear_mipmap, repeat_enable;
uniform sampler2D texture_heightmap_b : hint_default_black, filter_linear_mipmap, repeat_enable;
uniform float heightmap_scale : hint_range(-16.0, 16.0, 0.001) = 5.0;
uniform vec2 heightmap_flip = vec2(1.0, 1.0);
uniform vec3 uv1_scale = vec3(1.0, 1.0, 1.0);
uniform vec3 uv1_offset = vec3(0.0, 0.0, 0.0);
// extra
uniform vec2 blending_add_mul = vec2(0.0, 1.0); // add + mul
uniform vec2 roughness_add_mul = vec2(0.0, 1.0); // add + mul
uniform vec2 metallic_add_mul = vec2(0.0, 1.0); // add + mul
void vertex() {
UV = UV * uv1_scale.xy + uv1_offset.xy;
}
void fragment() {
vec2 base_uv = UV;
// get blending from vertex color red channel
float blending = clamp( (COLOR.r * blending_add_mul.y) + blending_add_mul.x, 0.0, 1.0 );
// height
vec3 view_dir = normalize(normalize(-VERTEX + EYE_OFFSET) * mat3(TANGENT * heightmap_flip.x, -BINORMAL * heightmap_flip.y, NORMAL));
float depth_a = 1.0 - texture(texture_heightmap_a, base_uv).r;
float depth_b = 1.0 - texture(texture_heightmap_b, base_uv).r;
float depth = mix(depth_a, depth_b, blending);
vec2 ofs = base_uv - view_dir.xy * depth * heightmap_scale * 0.01;
base_uv = ofs;
// albedo
vec3 albedo_tex_a = albedo_a.rgb * texture(texture_albedo_a, base_uv).rgb;
vec3 albedo_tex_b = albedo_b.rgb * texture(texture_albedo_b, base_uv).rgb;
ALBEDO = mix(albedo_tex_a, albedo_tex_b, blending);
// orm
vec4 orm_tex_a = texture(texture_orm_a, base_uv);
vec4 orm_tex_b = texture(texture_orm_b, base_uv);
AO = mix(orm_tex_a.r, orm_tex_b.r, blending);
float rough = mix(orm_tex_a.g, orm_tex_b.g, blending);
ROUGHNESS = clamp( (rough * roughness_add_mul.y) + roughness_add_mul.x, 0.0, 1.0);
float metal = mix(orm_tex_a.b, orm_tex_b.b, blending);
METALLIC = clamp( (metal * metallic_add_mul.y) + metallic_add_mul.x, 0.0, 1.0);
// normal
vec3 normal_a = (texture(texture_normal_a, base_uv).xyz - 0.5) * 2.0;
vec3 normal_b = (texture(texture_normal_b, base_uv).xyz - 0.5) * 2.0;
NORMAL_MAP = (normalize(mix(normal_a, normal_b, blending)) * 0.5) + 0.5;
NORMAL_MAP_DEPTH = mix(normal_scale_a, normal_scale_b, blending);
}