High Quality Post Process Outline
HOW TO USE:
1. Create a MeshInstance3D node with a QuadMesh and place it in your scene.
2. Set it’s size to 2×2.
3. Enable the “Flip Faces” option and add the maximum extra cull margin.
4. Create a new shader material with this shader.
5. Assign the material to the MeshInstance3D
LIMITATIONS:
– Does not work well with TAA enabled.
TESTED ENGINE VERSION: 4.0.3
Shader code
shader_type spatial;
render_mode unshaded, blend_mix, depth_draw_never, depth_test_disabled;
/*
AUTHOR: Hannah "EMBYR" Crawford
ENGINE_VERSION: 4.0.3
HOW TO USE:
1. Create a MeshInstance3D node and place it in your scene.
2. Set it's size to 2x2.
3. Enable the "Flip Faces" option.
4. Create a new shader material with this shader.
5. Assign the material to the MeshInstance3D
LIMITATIONS:
Does not work well with TAA enabled.
MOBILE_NOTES:
The mobile renderer does not have access to the normal_roughness texture
so we must rely on techniques to reconstruct this information from the
depth buffer.
If you require support on mobile please uncomment the SUPPORT_MOBILE line
below. I have done my best to match the appearance between the two modes
however, mobile does not take into account smooth-shaded faces.
The high-quality reconstruction method used on mobile is rather heavy on
texture samples. If you would like to use the lower-quality recontruction
method for better performance, please uncomment the NAIVE_NORMAL_RECONSTRUCTION
line below.
*/
//#define SUPPORT_MOBILE
//#define NAIVE_NORMAL_RECONSTRUCTION
group_uniforms outline;
uniform vec4 outlineColor: source_color = vec4(0.0, 0.0, 0.0, 0.78);
uniform float depth_threshold = 0.025;
uniform float normal_threshold : hint_range(0.0, 1.5) = 0.5;
uniform float normal_smoothing : hint_range(0.0, 1.0) = 0.25;
group_uniforms thickness;
uniform float max_thickness: hint_range(0.0, 5.0) = 1.3;
uniform float min_thickness = 0.5;
uniform float max_distance = 75.0;
uniform float min_distance = 2.0;
group_uniforms grazing_prevention;
uniform float grazing_fresnel_power = 5.0;
uniform float grazing_angle_mask_power = 1.0;
uniform float grazing_angle_modulation_factor = 50.0;
uniform sampler2D DEPTH_TEXTURE : hint_depth_texture, filter_linear, repeat_disable;
#ifndef SUPPORT_MOBILE
uniform sampler2D NORMR_TEXTURE : hint_normal_roughness_texture, filter_linear, repeat_disable;
#else
varying flat mat4 model_view_matrix;
#endif// !SUPPORT_MOBILE
struct UVNeighbors {
vec2 center;
vec2 left; vec2 right; vec2 up; vec2 down;
vec2 top_left; vec2 top_right; vec2 bottom_left; vec2 bottom_right;
};
struct NeighborDepthSamples {
float c_d;
float l_d; float r_d; float u_d; float d_d;
float tl_d; float tr_d; float bl_d; float br_d;
};
UVNeighbors getNeighbors(vec2 center, float width, float aspect) {
vec2 h_offset = vec2(width * aspect * 0.001, 0.0);
vec2 v_offset = vec2(0.0, width * 0.001);
UVNeighbors n;
n.center = center;
n.left = center - h_offset;
n.right = center + h_offset;
n.up = center - v_offset;
n.down = center + v_offset;
n.top_left = center - (h_offset - v_offset);
n.top_right = center + (h_offset - v_offset);
n.bottom_left = center - (h_offset + v_offset);
n.bottom_right = center + (h_offset + v_offset);
return n;
}
float getMinimumDepth(NeighborDepthSamples ds){
return min(ds.c_d, min(ds.l_d, min(ds.r_d, min(ds.u_d, min(ds.d_d, min(ds.tl_d, min(ds.tr_d, min(ds.bl_d, ds.br_d))))))));
}
float getLinearDepth(float depth, vec2 uv, mat4 inv_proj) {
vec3 ndc = vec3(uv * 2.0 - 1.0, depth);
vec4 view = inv_proj * vec4(ndc, 1.0);
view.xyz /= view.w;
return -view.z;
}
NeighborDepthSamples getLinearDepthSamples(UVNeighbors uvs, sampler2D depth_tex, mat4 invProjMat) {
NeighborDepthSamples result;
result.c_d = getLinearDepth(texture(depth_tex, uvs.center).r, uvs.center, invProjMat);
result.l_d = getLinearDepth(texture(depth_tex, uvs.left).r , uvs.left , invProjMat);
result.r_d = getLinearDepth(texture(depth_tex, uvs.right).r , uvs.right , invProjMat);
result.u_d = getLinearDepth(texture(depth_tex, uvs.up).r , uvs.up , invProjMat);
result.d_d = getLinearDepth(texture(depth_tex, uvs.down).r , uvs.down , invProjMat);
result.tl_d = getLinearDepth(texture(depth_tex, uvs.top_left).r, uvs.top_left, invProjMat);
result.tr_d = getLinearDepth(texture(depth_tex, uvs.top_right).r, uvs.top_right, invProjMat);
result.bl_d = getLinearDepth(texture(depth_tex, uvs.bottom_left).r, uvs.bottom_left, invProjMat);
result.br_d = getLinearDepth(texture(depth_tex, uvs.bottom_right).r, uvs.bottom_right, invProjMat);
return result;
}
float remap(float v, float from1, float to1, float from2, float to2) {
return (v - from1) / (to1 - from1) * (to2 - from2) + from2;
}
float fresnel(float amount, vec3 normal, vec3 view) {
return pow((1.0 - clamp(dot(normalize(normal), normalize(view)), 0.0, 1.0 )), amount);
}
float getGrazingAngleModulation(vec3 pixel_normal, vec3 view) {
float x = clamp(((fresnel(grazing_fresnel_power, pixel_normal, view) - 1.0) / grazing_angle_mask_power) + 1.0, 0.0, 1.0);
return (x + grazing_angle_modulation_factor) + 1.0;
}
float detectEdgesDepth(NeighborDepthSamples depth_samples, vec3 pixel_normal, vec3 view) {
float n_total =
depth_samples.l_d +
depth_samples.r_d +
depth_samples.u_d +
depth_samples.d_d +
depth_samples.tl_d +
depth_samples.tr_d +
depth_samples.bl_d +
depth_samples.br_d;
float t = depth_threshold * getGrazingAngleModulation(pixel_normal, view);
return step(t, n_total - (depth_samples.c_d * 8.0));
}
// Reconstruction helpers
// Source: https://www.reddit.com/r/godot/comments/v70p2k/improved_normal_from_depth/
#ifdef SUPPORT_MOBILE
vec3 reconstructWorldPosition(float depth, mat4 model_view, mat4 inv_proj, vec2 screen_uv, mat4 world, mat4 inv_cam){
vec4 pos = inverse(model_view) * inv_proj * vec4((screen_uv * 2.0 - 1.0), depth * 2.0 - 1.0, 1.0);
pos.xyz /= (pos.w + 0.0001 * (1.-abs(sign(pos.w))));
return (pos * inv_cam).xyz + world[3].xyz;
}
#ifndef NAIVE_NORMAL_RECONSTRUCTION
vec3 reconstructWorldNormal(sampler2D depth_tex, mat4 model_view, mat4 inv_proj, vec2 screen_uv, mat4 world, mat4 inv_cam, vec2 viewport_size) {
vec2 e = vec2(1.0 / viewport_size);
float c0 = texture(depth_tex, screen_uv ).r;
float l2 = texture(depth_tex, screen_uv - vec2(2,0) * e).r;
float l1 = texture(depth_tex, screen_uv - vec2(1,0) * e).r;
float r1 = texture(depth_tex, screen_uv + vec2(1,0) * e).r;
float r2 = texture(depth_tex, screen_uv + vec2(2,0) * e).r;
float b2 = texture(depth_tex, screen_uv - vec2(0,2) * e).r;
float b1 = texture(depth_tex, screen_uv - vec2(0,1) * e).r;
float t1 = texture(depth_tex, screen_uv + vec2(0,1) * e).r;
float t2 = texture(depth_tex, screen_uv + vec2(0,2) * e).r;
float dl = abs(l1 * l2 / (2.0 * l2 - l1) - c0);
float dr = abs(r1 * r2 / (2.0 * r2 - r1) - c0);
float db = abs(b1 * b2 / (2.0 * b2 - b1) - c0);
float dt = abs(t1 * t2 / (2.0 * t2 - t1) - c0);
vec3 ce = reconstructWorldPosition(c0, model_view, inv_proj, screen_uv, world, inv_cam);
vec3 dpdx = (dl<dr) ? ce-reconstructWorldPosition(l1, model_view, inv_proj, screen_uv - vec2(1,0) * e, world, inv_cam) :
-ce+reconstructWorldPosition(r1, model_view, inv_proj, screen_uv + vec2(1,0) * e, world, inv_cam) ;
vec3 dpdy = (db<dt) ? ce-reconstructWorldPosition(b1, model_view, inv_proj, screen_uv - vec2(0,1) * e, world, inv_cam) :
-ce+reconstructWorldPosition(t1, model_view, inv_proj, screen_uv + vec2(0,1) * e, world, inv_cam) ;
return normalize(cross(dpdx,dpdy));
}
#else
vec3 reconstructWorldNormal(sampler2D depth_tex, mat4 model_view, mat4 inv_proj, vec2 screen_uv, mat4 world, mat4 inv_cam, vec2 viewport_size) {
vec3 pos = reconstructWorldPosition(texture(depth_tex, screen_uv).x, model_view, inv_proj, screen_uv, world, inv_cam);
return normalize(cross(dFdx(pos), dFdy(pos)));
}
#endif//!NAIVE_NORMAL_RECONSTRUCTION
float detectEdgesNormalReconstructed(UVNeighbors uvs, sampler2D depth_tex, mat4 model_view, mat4 inv_proj, vec2 screen_uv, mat4 world, mat4 inv_cam, vec2 viewport_size){
vec3 n_u = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.up, world, inv_cam, viewport_size);
vec3 n_d = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.down, world, inv_cam, viewport_size);
vec3 n_l = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.left, world, inv_cam, viewport_size);
vec3 n_r = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.right, world, inv_cam, viewport_size);
vec3 n_tl = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.top_left, world, inv_cam, viewport_size);
vec3 n_tr = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.top_right, world, inv_cam, viewport_size);
vec3 n_bl = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.bottom_left, world, inv_cam, viewport_size);
vec3 n_br = reconstructWorldNormal(depth_tex, model_view, inv_proj, uvs.bottom_right, world, inv_cam, viewport_size);
vec3 normalFiniteDifference0 = n_tr - n_bl;
vec3 normalFiniteDifference1 = n_tl - n_br;
vec3 normalFiniteDifference2 = n_l - n_r;
vec3 normalFiniteDifference3 = n_u - n_d;
float edgeNormal = sqrt(
dot(normalFiniteDifference0, normalFiniteDifference0) +
dot(normalFiniteDifference1, normalFiniteDifference1) +
dot(normalFiniteDifference2, normalFiniteDifference2) +
dot(normalFiniteDifference3, normalFiniteDifference3)
) * 0.5;
return smoothstep(normal_threshold - normal_smoothing, normal_threshold + normal_smoothing, edgeNormal);
}
#else
float detectEdgesNormal(UVNeighbors uvs, sampler2D normTex, vec3 camDirWorld){
vec3 n_u = texture(normTex, uvs.up).xyz;
vec3 n_d = texture(normTex, uvs.down).xyz;
vec3 n_l = texture(normTex, uvs.left).xyz;
vec3 n_r = texture(normTex, uvs.right).xyz;
vec3 n_tl = texture(normTex, uvs.top_left).xyz;
vec3 n_tr = texture(normTex, uvs.top_right).xyz;
vec3 n_bl = texture(normTex, uvs.bottom_left).xyz;
vec3 n_br = texture(normTex, uvs.bottom_right).xyz;
vec3 normalFiniteDifference0 = n_tr - n_bl;
vec3 normalFiniteDifference1 = n_tl - n_br;
vec3 normalFiniteDifference2 = n_l - n_r;
vec3 normalFiniteDifference3 = n_u - n_d;
float edgeNormal = sqrt(
dot(normalFiniteDifference0, normalFiniteDifference0) +
dot(normalFiniteDifference1, normalFiniteDifference1) +
dot(normalFiniteDifference2, normalFiniteDifference2) +
dot(normalFiniteDifference3, normalFiniteDifference3)
);
return smoothstep(normal_threshold - normal_smoothing, normal_threshold + normal_smoothing, edgeNormal);
}
#endif//SUPPORT_MOBILE
void vertex() {
POSITION = vec4(VERTEX, 1.0);
#ifdef SUPPORT_MOBILE
model_view_matrix = INV_VIEW_MATRIX * mat4(VIEW_MATRIX[0],VIEW_MATRIX[1],VIEW_MATRIX[2],VIEW_MATRIX[3]);;
#endif
}
void fragment() {
float aspect = float(VIEWPORT_SIZE.y) / float(VIEWPORT_SIZE.x);
UVNeighbors n = getNeighbors(SCREEN_UV, max_thickness, aspect);
NeighborDepthSamples depth_samples = getLinearDepthSamples(n, DEPTH_TEXTURE, INV_PROJECTION_MATRIX);
float min_d = getMinimumDepth(depth_samples);
float thickness = clamp(remap(min_d, min_distance, max_distance, max_thickness, min_thickness), min_thickness, max_thickness);
float fade_a = clamp(remap(min_d, min_distance, max_distance, 1.0, 0.0), 0.0, 1.0);
n = getNeighbors(SCREEN_UV, thickness, aspect);
depth_samples = getLinearDepthSamples(n, DEPTH_TEXTURE, INV_PROJECTION_MATRIX);
#ifndef SUPPORT_MOBILE
vec3 pixel_normal = texture(NORMR_TEXTURE, SCREEN_UV).xyz;
#else
vec3 pixel_normal = reconstructWorldNormal(DEPTH_TEXTURE, model_view_matrix, INV_PROJECTION_MATRIX, SCREEN_UV, MODEL_MATRIX, INV_VIEW_MATRIX, VIEWPORT_SIZE.xy);
#endif
float depthEdges = detectEdgesDepth(depth_samples, pixel_normal, VIEW);
#ifndef SUPPORT_MOBILE
float normEdges = min(detectEdgesNormal(n, NORMR_TEXTURE, CAMERA_DIRECTION_WORLD), 1.0);
#else
float normEdges = min(detectEdgesNormalReconstructed(n, DEPTH_TEXTURE, model_view_matrix, INV_PROJECTION_MATRIX, SCREEN_UV, MODEL_MATRIX, INV_VIEW_MATRIX, VIEWPORT_SIZE.xy), 1.0);
#endif
ALBEDO.rgb = outlineColor.rgb;
ALPHA = max(depthEdges, normEdges) * outlineColor.a * fade_a;
}
