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shading #15

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merged 12 commits into from
Dec 10, 2023
Merged

shading #15

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06c0a8d
renderer environment
theolundqvist Dec 9, 2023
cf563ce
Merge branch 'fvta-new'
theolundqvist Dec 9, 2023
3386f30
normals
theolundqvist Dec 9, 2023
abe76ca
normals
theolundqvist Dec 9, 2023
e761348
correct normal
theolundqvist Dec 9, 2023
42730f5
HDR pipeline
theolundqvist Dec 9, 2023
4752fb1
ambient occlusion start
theolundqvist Dec 9, 2023
92ddd39
world pos and uvw
theolundqvist Dec 10, 2023
3d06e21
fix hash holes
theolundqvist Dec 10, 2023
ea8b8ee
normals fixed again?
theolundqvist Dec 10, 2023
e5d59df
fix epsilon values
theolundqvist Dec 10, 2023
91f3de5
fix ambient occlusion
theolundqvist Dec 10, 2023
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258 changes: 214 additions & 44 deletions shaders/EDAN35/voxel.frag
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
#version 410
#define Epsilon 0.0000001
#define Epsilon 0.000001

// uniform vec3 light_position;
uniform vec3 camera_position;
Expand All @@ -22,19 +22,63 @@ out vec4 fColor;

float isInside(vec3 pos){
// this works but did not notice performance difference
/*
return step(0.0, pos.x)*step(pos.x, 1.0) *
step(0.0, pos.y)*step(pos.y, 1.0) *
step(0.0, pos.z)*step(pos.z, 1.0);
/*
if (pos.x < 0.0 || pos.x > 1.0) return false;
if (pos.y < 0.0 || pos.y > 1.0) return false;
if (pos.z < 0.0 || pos.z > 1.0) return false;
return true;
*/
*/
if (pos.x < 0.0 || pos.x > 1.0) return 0.0;
if (pos.y < 0.0 || pos.y > 1.0) return 0.0;
if (pos.z < 0.0 || pos.z > 1.0) return 0.0;
return 1.0;
}

struct start_t{
vec3 pos;
vec3 normal;
};

vec3 uvw_to_normal(vec3 uvw){
// find normal
vec3 hit_to_center = uvw - vec3(0.5);
vec3 abs_hit_to_center = abs(hit_to_center);
float max_component = max(max(abs_hit_to_center.x, abs_hit_to_center.y), abs_hit_to_center.z);

vec3 normal;
if (abs_hit_to_center.x == max_component) {
normal = vec3(sign(hit_to_center.x), 0.0, 0.0);
} else if (abs_hit_to_center.y == max_component) {
normal = vec3(0.0, sign(hit_to_center.y), 0.0);
} else {
normal = vec3(0.0, 0.0, sign(hit_to_center.z));
}
return normal;
}

vec2 uvw_to_uv(vec3 uvw){
if(uvw.x == 0.0 && uvw.y == 0.0 && uvw.z == 0.0) return vec2(0.0, 0.0);
if(uvw.x == 1.0 && uvw.y == 1.0 && uvw.z == 1.0) return vec2(1.0, 1.0);
if(uvw.x == 0.0 && uvw.y == 1.0 && uvw.z == 1.0) return vec2(0.0, 1.0);
if(uvw.x == 1.0 && uvw.y == 0.0 && uvw.z == 1.0) return vec2(1.0, 0.0);
if(uvw.x == 1.0 && uvw.y == 1.0 && uvw.z == 0.0) return vec2(1.0, 0.0);
if(uvw.x == 0.0 && uvw.y == 0.0 && uvw.z == 1.0) return vec2(0.0, 1.0);
vec3 tangents = vec3(1) - abs(uvw_to_normal(uvw));
vec3 a, b;
if (tangents.x == 0.0f) {
a = vec3(0, 1, 0);
b = vec3(0, 0, 1);
} else if (tangents.y == 0.0f) {
a = vec3(1, 0, 0);
b = vec3(0, 0, 1);
} else {
a = vec3(1, 0, 0);
b = vec3(0, 1, 0);
}
return vec2(dot(b, uvw), dot(a, uvw));
}

// Work In Progress
vec3 findStartPos(){
start_t findStartPos(){
vec3 dir = normalize(fV);
// x/0 is undefined behaviour
//if(dir.x == 0.0) dir.x = 0.0000001;
Expand All @@ -61,95 +105,221 @@ vec3 findStartPos(){


// first intersection with cube
vec3 intersect = origin + dir * (tmin + 0.00001);
vec3 near = origin + dir * (tmin + Epsilon * 10.0f);
vec3 far = origin + dir * (tmax - Epsilon);
// if camera is closer to the pos on the backface than the intersect, return the camera pos
if (length(intersect-pos) > length(model_cam_pos - pos)){
return model_cam_pos;// 0.0 - 1.0
if (length(near-pos) > length(model_cam_pos - pos)){
return start_t(model_cam_pos, vec3(0, 0, 0));// 0.0 - 1.0
}
return intersect;
return start_t(near, uvw_to_normal(near));
}

struct hit_t {
vec3 voxel;
float depth;
vec3 voxel_pos;
vec3 pixel_pos;
vec3 uvw;
vec2 uv;
vec3 normal;
int material;
};

hit_t fixed_step(){
vec3 V = normalize(fV) * voxel_size/15;// fixed step
vec3 P = findStartPos();// P is in 0-1.0 space
vec3 last_voxel = floor(P * voxel_size);
for (int i = 0; i < 700; i++){
start_t start = findStartPos();// P is in 0-1.0 space
vec3 P = start.pos;
int max_step = int(15*15/voxel_size);
for (int i = 0; i < max_step; i++){
if (isInside(P) < 0.5) discard;
vec3 norm = floor(P * voxel_size) - last_voxel;
last_voxel -= norm;
int material = int(round(texture(volume, P).r*255));
if (material != 0) return hit_t(P, norm, material);
if (material != 0) {
float t = length(P - start.pos);
vec3 index = floor(P/voxel_size);
return hit_t(t, index, P, (P - vec3(index))/voxel_size, uvw_to_uv((P - vec3(index))/voxel_size), start.normal, material);
}
P += V;
}
discard;
}


float luminance(vec3 v)
{
return dot(v, vec3(0.2126f, 0.7152f, 0.0722f));
}
vec3 reinhard_jodie(vec3 v)
{
float l = luminance(v);
vec3 tv = v / (1.0f + v);
return mix(v / (1.0f + l), tv, tv);
}
// have not tried yet
vec3 shade(hit_t hit){
vec3 V=normalize(fV);
vec3 N=normalize(hit.voxel-hit.normal);
vec3 N=normalize(hit.normal);
vec3 L=normalize(light_direction);

float diffuse_co=max(dot(L, N), 0);
vec3 R=normalize(reflect(-L, N));
float specular_co=pow(max(dot(R, V), 0.0), 0.5);
float diffuse_co= 1.7f * max(dot(L, N), 0);
float specular_co = 0.0;
bool blinn = true;
if (blinn)
{
vec3 halfwayDir = normalize(L -V);
specular_co = pow(max(dot(N, halfwayDir), 0.0), 4.0);
}
else
{
vec3 R = reflect(-L, N);
specular_co = pow(max(dot(-V, R), 0.0), 1.1);
}
//vec3 voxel_color=vec3(1, 0, 0);
vec3 voxel_color=diffuse_co*vec3(0, 1, 0)+specular_co*vec3(0, 0, 1);//+specular_co*vec3(0, 0, 1);
// use material color
return voxel_color;
vec3 mat_color = vec3(hit.material/255.0, 0, 0);
vec3 ambient=vec3(0.4) * mat_color;
vec3 v = ambient + diffuse_co * mat_color + specular_co * vec3(0.6);//+specular_co*vec3(0, 0, 1);
return reinhard_jodie(v);
}

// finally works omg
// got some help from here
// https://www.shadertoy.com/view/4dS3RG
hit_t fvta_step(){
vec3 ro = findStartPos();
start_t start = findStartPos();
vec3 ro = start.pos;
vec3 normal = start.normal;
vec3 rd = normalize(fV);
vec3 voxel_pos = voxel_size * floor(ro * (1./voxel_size));
vec3 voxel_index = floor(ro * (1./voxel_size));
vec3 voxel_pos = voxel_size * voxel_index;
vec3 rs = sign(rd);
vec3 deltaDist = voxel_size/rd;
vec3 sideDist = ((voxel_pos-ro)/voxel_size + 0.5 + rs * 0.5) * deltaDist;
voxel_pos = voxel_size * (floor(ro * (1./voxel_size)) + 0.1);
//voxel_pos = voxel_size * (voxel_index + 0.1);
int max_steps = int(3.0/voxel_size);

vec3 final_pos = ro * 1./voxel_size;
float t = 0.0;
vec3 pos = ro;//voxel_size * (voxel_index + 0.1);
vec3 uvw = (pos - voxel_pos)/voxel_size;
vec2 uv = uvw_to_uv(uvw);

for (int i = 0; i < max_steps; i++){
if (isInside(voxel_pos) < 0.5) {
if (isInside(pos) < 0.5) {
//return hit_t(t, voxel_pos, pos, uvw, uv, vec3(1,0,0), 0);
discard;
}
int mat = int(round(texture(volume, voxel_pos).r*255));
// black magic compare between sideDist.x < sideDist.y && sideDist.x < sideDist.z etc
vec3 mm = step(sideDist.xyz, sideDist.yxy) * step(sideDist.xyz, sideDist.zzx);
vec3 norm = -mm * rs;
int mat = int(round(texture(volume, pos).r*255));
if (mat > 0){
return hit_t(voxel_pos, norm, mat);
return hit_t(t, voxel_pos, pos, uvw, uv, normal, mat);
}
voxel_pos += voxel_size * -norm;
sideDist += -norm * deltaDist;
/*
if (sideDist.x < sideDist.y && sideDist.x < sideDist.z) {
// X-axis traversal.
normal = -vec3(1, 0, 0) * rs;
t = sideDist.x * rd;
} else if (sideDist.y < sideDist.z) {
// Y-axis traversal.
normal = -vec3(0, 1, 0) * rs;
t = sideDist.y * rd;
} else {
// Z-axis traversal.
normal = -vec3(0, 0, 1) * rs;
t = sideDist.z * rd;
}
*/
// black magic compare between sideDist.x < sideDist.y && sideDist.x < sideDist.z etc
vec3 mm = step(sideDist.xyz, sideDist.yxy) * step(sideDist.xyz, sideDist.zzx);
normal = -mm * rs;

voxel_pos += voxel_size * -normal;

// other stuff that is nice to know
vec3 mini = ((voxel_pos-ro)/voxel_size + 0.5 - 0.5*vec3(rs))*deltaDist;
t = max (mini.x, max (mini.y, mini.z));
pos = ro + rd * (t + Epsilon);
uvw = (pos - voxel_pos)/voxel_size;
uv = vec2(dot(mm.yzx, uvw), dot(mm.zxy, uvw));

sideDist += -normal * deltaDist;
}
discard;
}
mat4 rotationX(in float angle) {
return mat4(1.0, 0, 0, 0,
0, cos(angle), -sin(angle), 0,
0, sin(angle), cos(angle), 0,
0, 0, 0, 1);
}

mat4 rotationY(in float angle) {
return mat4(cos(angle), 0, sin(angle), 0,
0, 1.0, 0, 0,
-sin(angle), 0, cos(angle), 0,
0, 0, 0, 1);
}

mat4 rotationZ(in float angle) {
return mat4(cos(angle), -sin(angle), 0, 0,
sin(angle), cos(angle), 0, 0,
0, 0, 1, 0,
0, 0, 0, 1);
}
float ao(hit_t hit){
//float edge_x = clamp(pow(abs(hit.uv.x-0.5)+0.5, 20), 0, 1);
//float edge_y = clamp(pow(abs(hit.uv.y-0.5)+0.5, 20), 0, 1);
//return max(edge_x, edge_y);
vec3 N=normalize(hit.normal);
vec3 P = hit.pixel_pos;
float ao = 0.0;
int nbr_samples = 4;
float r_rel = 0.04;
// save some texture reads by only sampling edges
if(hit.uv.x > r_rel && hit.uv.x < 1-r_rel && hit.uv.y > r_rel && hit.uv.y < 1-r_rel) return 1.0;
float r = voxel_size * r_rel;
//if(hit.uv.y > r && hit.uv.y < 1.0 - r) return 1.0;
vec3 sphere_center = P + N * r;
vec3 tangent = vec3(1) - abs(N);
mat4 rot = mat4(1.0f);
float angle = 3.14159265359*2.0 * 1/nbr_samples;
if(abs(N.x) > 0.01){
rot = rotationX(angle);
}
else if(abs(N.y) > 0.01){
rot = rotationY(angle);
}
else {
rot = rotationZ(angle);
}
for (int i = 0; i < nbr_samples; i++){
// rotate bitangent
tangent = normalize((rot * vec4(tangent,1)).xyz);
vec3 sample_point = sphere_center + tangent * r;
if (isInside(sample_point) < 0.5) continue;
float material = texture(volume, sample_point).r * 255.0;
if (material > 0.0){
ao += 1.0/(nbr_samples*2.0);
}
}
return mix(smoothstep(0, 1, 1-2*ao), 1 , 1-ao);
}

void main()
{
// custom front face culling to do it based on cam pos
if (face_dot_v < 0.0) discard;
//if (face_dot_v < 0.0) discard;

//vec3 color = findStartPos();
hit_t hit;
//hit = fixed_step();
hit = fvta_step();
if (isInside(hit.pixel_pos - 0.01 * hit.normal * voxel_size) < 0.5){
discard;
}
vec3 color = vec3(hit.material/255.0, 0, 0);
color = shade(hit);
color *= ao(hit);
//color = hit.pixel_pos;
//color = hit.voxel_pos;
//color = normalize(hit.normal) * 0.5 + 0.5;
//color = hit.uvw;
//color = vec3(hit.uv, 1.0);
//color = vec3(hit.depth);

vec3 color = vec3(hit.voxel);
//color = shade(hit);
//color = normalize(hit.last_voxel - hit.voxel);

fColor = vec4(color, 1.0);
}
Expand Down
4 changes: 2 additions & 2 deletions src/EDAN35/project.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -115,7 +115,7 @@ void edan35::Project::run() {


glClearDepthf(1.0f);
glClearColor(1.0f, 1.0f, 0.94f, 1.0f);
glClearColor(0.85f, 0.85f, 0.74f, 1.0f);
glEnable(GL_DEPTH_TEST);

auto lastTime = std::chrono::high_resolution_clock::now();
Expand Down Expand Up @@ -190,7 +190,7 @@ void edan35::Project::run() {

mWindowManager.NewImGuiFrame();

glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

// RENDER
app->render(show_basis, basis_length_scale, basis_thickness_scale, dt);
Expand Down
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