Triangle normals and lighting are computed inside the fragment shader for the multi-material painting gizmo.

It results in a six-fold reduction of the amount of data transferred into GPU because there is no need to duplicate vertices for every triangle. Also, normals aren't needed to be transferred to GPU.
This commit is contained in:
Lukáš Hejl 2021-06-25 18:09:53 +02:00
parent a467d0e30e
commit 6194e67e68
4 changed files with 233 additions and 68 deletions

View file

@ -1,5 +1,19 @@
#version 110
#define INTENSITY_CORRECTION 0.6
// normalized values for (-0.6/1.31, 0.6/1.31, 1./1.31)
const vec3 LIGHT_TOP_DIR = vec3(-0.4574957, 0.4574957, 0.7624929);
#define LIGHT_TOP_DIFFUSE (0.8 * INTENSITY_CORRECTION)
#define LIGHT_TOP_SPECULAR (0.125 * INTENSITY_CORRECTION)
#define LIGHT_TOP_SHININESS 20.0
// normalized values for (1./1.43, 0.2/1.43, 1./1.43)
const vec3 LIGHT_FRONT_DIR = vec3(0.6985074, 0.1397015, 0.6985074);
#define LIGHT_FRONT_DIFFUSE (0.3 * INTENSITY_CORRECTION)
#define INTENSITY_AMBIENT 0.3
const vec3 ZERO = vec3(0.0, 0.0, 0.0);
const vec3 GREEN = vec3(0.0, 0.7, 0.0);
const vec3 YELLOW = vec3(0.5, 0.7, 0.0);
@ -42,14 +56,42 @@ vec3 sinking_color(vec3 color)
return (mod(model_pos.x + model_pos.y + model_pos.z, BANDS_WIDTH) < (0.5 * BANDS_WIDTH)) ? mix(color, ZERO, 0.6666) : color;
}
uniform bool compute_triangle_normals_in_fs;
void main()
{
if (any(lessThan(clipping_planes_dots, ZERO)))
discard;
vec3 color = uniform_color.rgb;
vec3 color = uniform_color.rgb;
float alpha = uniform_color.a;
if (slope.actived && world_normal_z < slope.normal_z - EPSILON)
{
vec2 intensity_fs = intensity;
vec3 eye_normal_fs = eye_normal;
float world_normal_z_fs = world_normal_z;
if (compute_triangle_normals_in_fs) {
vec3 triangle_normal = normalize(cross(dFdx(model_pos.xyz), dFdy(model_pos.xyz)));
// First transform the normal into camera space and normalize the result.
eye_normal_fs = normalize(gl_NormalMatrix * triangle_normal);
// Compute the cos of the angle between the normal and lights direction. The light is directional so the direction is constant for every vertex.
// Since these two are normalized the cosine is the dot product. We also need to clamp the result to the [0,1] range.
float NdotL = max(dot(eye_normal_fs, LIGHT_TOP_DIR), 0.0);
intensity_fs = vec2(0.0, 0.0);
intensity_fs.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE;
vec3 position = (gl_ModelViewMatrix * model_pos).xyz;
intensity_fs.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(position), reflect(-LIGHT_TOP_DIR, eye_normal_fs)), 0.0), LIGHT_TOP_SHININESS);
// Perform the same lighting calculation for the 2nd light source (no specular applied).
NdotL = max(dot(eye_normal_fs, LIGHT_FRONT_DIR), 0.0);
intensity_fs.x += NdotL * LIGHT_FRONT_DIFFUSE;
// z component of normal vector in world coordinate used for slope shading
world_normal_z_fs = slope.actived ? (normalize(slope.volume_world_normal_matrix * triangle_normal)).z : 0.0;
}
if (slope.actived && world_normal_z_fs < slope.normal_z - EPSILON) {
color = vec3(0.7, 0.7, 1.0);
alpha = 1.0;
}
@ -60,8 +102,8 @@ void main()
color = (abs(world_pos_z) < 0.05) ? WHITE : sinking_color(color);
#ifdef ENABLE_ENVIRONMENT_MAP
if (use_environment_tex)
gl_FragColor = vec4(0.45 * texture2D(environment_tex, normalize(eye_normal).xy * 0.5 + 0.5).xyz + 0.8 * color * intensity.x, alpha);
gl_FragColor = vec4(0.45 * texture2D(environment_tex, normalize(eye_normal_fs).xy * 0.5 + 0.5).xyz + 0.8 * color * intensity_fs.x, alpha);
else
#endif
gl_FragColor = vec4(vec3(intensity.y) + color * intensity.x, alpha);
gl_FragColor = vec4(vec3(intensity_fs.y) + color * intensity_fs.x, alpha);
}

View file

@ -54,22 +54,26 @@ varying float world_pos_z;
varying float world_normal_z;
varying vec3 eye_normal;
uniform bool compute_triangle_normals_in_fs;
void main()
{
// First transform the normal into camera space and normalize the result.
eye_normal = normalize(gl_NormalMatrix * gl_Normal);
// Compute the cos of the angle between the normal and lights direction. The light is directional so the direction is constant for every vertex.
// Since these two are normalized the cosine is the dot product. We also need to clamp the result to the [0,1] range.
float NdotL = max(dot(eye_normal, LIGHT_TOP_DIR), 0.0);
if (!compute_triangle_normals_in_fs) {
// First transform the normal into camera space and normalize the result.
eye_normal = normalize(gl_NormalMatrix * gl_Normal);
intensity.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE;
vec3 position = (gl_ModelViewMatrix * gl_Vertex).xyz;
intensity.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(position), reflect(-LIGHT_TOP_DIR, eye_normal)), 0.0), LIGHT_TOP_SHININESS);
// Compute the cos of the angle between the normal and lights direction. The light is directional so the direction is constant for every vertex.
// Since these two are normalized the cosine is the dot product. We also need to clamp the result to the [0,1] range.
float NdotL = max(dot(eye_normal, LIGHT_TOP_DIR), 0.0);
// Perform the same lighting calculation for the 2nd light source (no specular applied).
NdotL = max(dot(eye_normal, LIGHT_FRONT_DIR), 0.0);
intensity.x += NdotL * LIGHT_FRONT_DIFFUSE;
intensity.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE;
vec3 position = (gl_ModelViewMatrix * gl_Vertex).xyz;
intensity.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(position), reflect(-LIGHT_TOP_DIR, eye_normal)), 0.0), LIGHT_TOP_SHININESS);
// Perform the same lighting calculation for the 2nd light source (no specular applied).
NdotL = max(dot(eye_normal, LIGHT_FRONT_DIR), 0.0);
intensity.x += NdotL * LIGHT_FRONT_DIFFUSE;
}
model_pos = gl_Vertex;
// Point in homogenous coordinates.
@ -77,19 +81,17 @@ void main()
world_pos_z = world_pos.z;
// compute deltas for out of print volume detection (world coordinates)
if (print_box.actived)
{
if (print_box.actived) {
delta_box_min = world_pos.xyz - print_box.min;
delta_box_max = world_pos.xyz - print_box.max;
}
else
{
} else {
delta_box_min = ZERO;
delta_box_max = ZERO;
}
// z component of normal vector in world coordinate used for slope shading
world_normal_z = slope.actived ? (normalize(slope.volume_world_normal_matrix * gl_Normal)).z : 0.0;
if (!compute_triangle_normals_in_fs)
world_normal_z = slope.actived ? (normalize(slope.volume_world_normal_matrix * gl_Normal)).z : 0.0;
gl_Position = ftransform();
// Fill in the scalars for fragment shader clipping. Fragments with any of these components lower than zero are discarded.