opengles 2.0 per-vertex lighting - opengl-es

VertexShader:
varying vec4 diffuseColor;
uniform mat4 modelViewProj;
uniform mat4 modelViewTranspose;
attribute vec3 streamNormal;
attribute vec3 streamPosition;
void main() {
gl_Position = modelViewProj * streamPosition;
diffuseColor = max(0, dot(normalize(modelViewTranspose * streamNormal), vec3(0,0,1)) * vec4(1,0,0,1);
}
PixelShader:
varying vec4 diffuseColor;
void main() {
gl_FragColor = diffuseColor;
}
the matrix is by left-hand (row major), modelViewProj calculated by C++, it is the world * view * projection, modelViewTranspose = transpose(inverse(world * view)).
The render result is not right, I cannot see any thing, but if I set gl_FragColor always to vec4(1,1,1,1), the model render is no problem. Does my code have errors? or other problems?

Related

Incorrect lighting of a bone-animated object on OpenGL ES 2.0

I imported a simple animated object from Blender on three bones. I have a problem with lighting of skinning object. I set a light position above the object:
const vec3 lightPosition = vec3(0.0, 15.0, 0.0);
You can see that lighting is affected under object too:
precision mediump float;
attribute vec3 aPosition;
attribute vec4 aNormal;
attribute vec2 aTexCoord;
attribute vec3 aJoints;
attribute vec3 aWeights;
uniform mat4 uMvpMatrix;
uniform mat4 uModelMatrix;
uniform mat4 uNormalMatrix;
uniform mat4 uTransforms[3];
varying vec3 vPosition;
varying vec3 vNormal;
varying vec2 vTexCoord;
void main()
{
vec4 totalLocalPos = vec4(0.0);
vec4 totalNormal = vec4(0.0);
for (int i = 0; i < 3; i++)
{
int jointIndex = int(aJoints[i]);
mat4 jointTransform = uTransforms[jointIndex];
vec4 posePosition = jointTransform * vec4(aPosition, 1.0);
totalLocalPos += posePosition * aWeights[i];
vec4 worldNormal = jointTransform * aNormal;
totalNormal += worldNormal * aWeights[i];
}
gl_Position = uMvpMatrix * totalLocalPos;
vPosition = vec3(uModelMatrix * vec4(aPosition, 1.0));
vNormal = totalNormal.xyz;
vTexCoord = aTexCoord;
}
precision mediump float;
const vec3 lightColor = vec3(0.8, 0.8, 0.8);
const vec3 lightPosition = vec3(0.0, 15.0, 0.0);
const vec3 ambientLight = vec3(0.3, 0.3, 0.3);
uniform sampler2D uSampler;
varying vec3 vPosition;
varying vec3 vNormal;
varying vec2 vTexCoord;
void main()
{
vec4 color = texture2D(uSampler, vTexCoord);
vec3 normal = normalize(vNormal);
vec3 lightDirection = normalize(lightPosition - vPosition);
float nDotL = max(dot(lightDirection, normal), 0.0);
vec3 diffuse = lightColor * color.rgb * nDotL;
vec3 ambient = ambientLight * color.rgb;
gl_FragColor = vec4(diffuse + ambient, color.a);
}
Aroch helped me on Russian forum here:
the normal only needs to be rotated.
Now it works as it should. I took shaders (except lighting model) from source for a video tutorial series from ThinMatrix. It works fine for ThinMatrix. This means that for some reason its lighting model is not affected by the translation of the normal vector. It will be necessary to figure out later why he does not have this problem. I made the transfer of the array of rotation matrices a separate uniform:
uniform mat4 uTransforms[3];
uniform mat4 uRotations[3];
...
for (int i = 0; i < 3; i++)
{
int jointIndex = int(aJoints[i]);
mat4 jointTransform = uTransforms[jointIndex];
vec4 posePosition = jointTransform * vec4(aPosition, 1.0);
totalLocalPos += posePosition * aWeights[i];
mat4 rotation = uRotations[jointIndex];
vec4 worldNormal = rotation * aNormal;
totalNormal += worldNormal * aWeights[i];
}
Gif Animation: https://gamedev.ru/files/images/solution-with-lighting.gif

Shader wireframe of an object

I want to see a wireframe of an object without the diagonals like
Currently, I add lines according to the vertices, the problem is after I have several of those I experience a major performance degradation.
The examples here are either too new for my version of Three or don't work (I commented there about it).
So I want to try to implement a shader instead.
I tried to use this shader: https://stackoverflow.com/a/31610464/4279201 but it breaks the shape to parts and I'm getting WebGL errors.
That's how I use it:
const vertexShader = `
varying vec2 vUv;
void main() {
vUv = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position,1.0);
}
`
const fragmentShader = `
#version 150 compatibility
flat in float diffuse;
flat in float specular;
flat in vec3 edge_mask;
in vec2 bary;
uniform float mesh_width = 1.0;
uniform vec3 mesh_color = vec3(0.0, 0.0, 0.0);
uniform bool lighting = true;
out vec4 frag_color ;
float edge_factor(){
vec3 bary3 = vec3(bary.x, bary.y, 1.0 - bary.x - bary.y);
vec3 d = fwidth(bary3);
vec3 a3 = smoothstep(vec3(0.0, 0.0, 0.0), d * mesh_width, bary3);
a3 = vec3(1.0, 1.0, 1.0) - edge_mask + edge_mask * a3;
return min(min(a3.x, a3.y), a3.z);
}
void main() {
float s = (lighting && gl_FrontFacing) ? 1.0 : -1.0;
vec4 Kdiff = gl_FrontFacing ?
gl_FrontMaterial.diffuse : gl_BackMaterial.diffuse;
float sdiffuse = s * diffuse;
vec4 result = vec4(0.1, 0.1, 0.1, 1.0);
if (sdiffuse > 0.0) {
result += sdiffuse * Kdiff +
specular * gl_FrontMaterial.specular;
}
frag_color = (mesh_width != 0.0) ?
mix(vec4(mesh_color, 1.0), result, edge_factor()) :
result;
}`
...
const uniforms = {
color: {
value: new THREE.Vector4(0, 0, 1, 1),
type: 'v4'
}
}
const material = new THREE.ShaderMaterial({
fragmentShader: data.fragmentShader,
vertexShader: data.vertexShader,
uniforms
})
this._viewer.impl.matman().addMaterial(
data.name, material, true)
const fragList = this._viewer.model.getFragmentList()
this.toArray(fragIds).forEach((fragId) => {
fragList.setMaterial(fragId, material)
})
So to implement this shader, is the right approach would be to basically check the angle between every two vertices, and draw a line if the degree is 90?
How can I have access to all the vertices of the shape from the vertex shader?
And how can I tell the fragment shader to draw a line between two vertices that match the above condition? (also to leave the default shading for everything else as is)
I'm using Autodesk viewer that uses Three.js rev 71.
// -- Vertex Shader --
precision mediump float;
// Input from buffers
attribute vec3 aPosition;
attribute vec2 aBaryCoord;
// Value interpolated accross pixels and passed to the fragment shader
varying vec2 vBaryCoord;
// Uniforms
uniform mat4 uModelMatrix;
uniform mat4 uViewMatrix;
uniform mat4 uProjMatrix;
void main() {
vBaryCoord = aBaryCoord;
gl_Position = uProjMatrix * uViewMatrix * uModelMatrix * vec4(aPosition,1.0);
}
// ---------------------
// -- Fragment Shader --
// This shader doesn't perform any lighting
precision mediump float;
varying vec2 vBaryCoord;
uniform vec3 uMeshColour;
float edgeFactor() {
vec3 d = fwidth(vBaryCoord);
vec3 a3 = smoothstep(vec3(0.0,0.0,0.0),d * 1.5,vBaryCoord);
return min(min(a3.x,a3.y),a3.z);
}
void main() {
gl_FragColor = vec4(uMeshColour,(1.0 - edgeFactor()) * 0.95);
}
// ---------------------
/*
This code isn't tested so take it with a grain of salt
Idea taken from
http://codeflow.org/entries/2012/aug/02/easy-wireframe-display-with-barycentric-coordinates/
*/

Three.JS: Gaussian blur in GLSL shader

I have this vert/frag shader, which is using vertex data and two textures.
I am trying to apply post blur effect, but having only rectangles after it.
vert:
attribute float type;
attribute float size;
attribute float phase;
attribute float increment;
uniform float time;
uniform vec2 resolution;
uniform sampler2D textureA;
uniform sampler2D textureB;
varying float t;
void main() {
t = type;
vec4 mvPosition = modelViewMatrix * vec4(position, 1.0 );
if(t == 0.) {
gl_PointSize = size * 0.8;
} else {
gl_PointSize = size * sin(phase + time * increment) * 12.;
}
gl_Position = projectionMatrix * mvPosition;
}
frag:
uniform float time;
uniform vec2 resolution;
uniform sampler2D textureA;
uniform sampler2D textureB;
varying float t;
uniform sampler2D texture;
vec4 blur2D(sampler2D image, vec2 uv, vec2 resolution, vec2 direction) {
vec4 color = vec4(0.0);
vec2 off1 = vec2(1.3846153846) * direction;
vec2 off2 = vec2(3.2307692308) * direction;
color += texture2D(image, uv) * 0.2270270270;
color += texture2D(image, uv + (off1 / resolution)) * 0.3162162162;
color += texture2D(image, uv - (off1 / resolution)) * 0.3162162162;
color += texture2D(image, uv + (off2 / resolution)) * 0.0702702703;
color += texture2D(image, uv - (off2 / resolution)) * 0.0702702703;
return color;
}
void main() {
vec2 direction = vec2(1., 0.);
vec2 uv = vec2(gl_FragCoord.xy / resolution.xy);
gl_FragColor = vec4(vec3(1.0, 1.0, 1.0), 1.);
if(t == 0.){
gl_FragColor = gl_FragColor * texture2D(textureA, gl_PointCoord);
} else {
gl_FragColor = gl_FragColor * texture2D(textureB, gl_PointCoord);
}
gl_FragColor = blur2D(texture, uv, resolution.xy, direction);
}
How could I 'bake' everything before applying blurring to texture2D/sampler2D?
Maybe I need to create another blur shader and pass texture2D to it?

Same texture offseting different position in the fragment shader using threejs rendering engine

My vertex shader:
varying vec2 texCoord;
void main() {
texCoord = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
My fragment shader:
varying vec2 texCoord;
uniform sampler2D texture1;
uniform sampler2D texture2;
uniform float multiplier;
void main( void ) {
vec3 tex1 = texture2D(texture1, texCoord).xyz ;
vec3 tex2 = texture2D(texture2, texCoord).xyz ;
vec3 finaltex = mix( tex1, tex2, multiplier) ;
gl_FragColor = vec4(finaltex , 1.0);
}
Now this work very well when i run using the two texture.check http://shaderfrog.com/app/view/68 for the multiplier action.
But now what I want is I am having texture like this:
So with the single texture I want to index the offset of my texCoord so that I just need to sample one texture and I can get three representation form this like:
var shaderMaterial = new THREE.ShaderMaterial({
uniforms:{
texture1: { type: "t", value: texture1 }
},
vertexShader: document.getElementById( 'vertexShader' ).textContent,
fragmentShader: document.getElementById( 'fragmentShader' ).textContent
});
Can offset my tri-color in the fragment shader. or Some one can help me modifying the fragment shader so that I can pass uniform to index my tri-color into individual Yellow,pink,red.
So either from shader or threejs I can get help regarding same.
I have done reference using two texture because I want to interpolate with cross fade effect on the texture same I want cross fade using fragment shader (independent to this I have already achieve by the texture.offset.x = currentColoum / horizontal and texture.offset.y = currentRow / Vertical;
I found the answer to this question, even implemented into application :D.
vertexShader:
void main() {
texCoord = uv;
gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
}
FragmentShader:
varying vec2 texCoord;
uniform sampler2D texture;
uniform vec2 offset_current;
uniform vec2 offset_next;
uniform float multiplier;
void main( void ) {
vec2 offset1 = offset_current + vec2( texCoord.x* 1.0, texCoord.y * 0.333333);
vec2 offset2 = offset_next + vec2( texCoord.x* 1.0, texCoord.y * 0.333333);
vec3 tex1 = texture2D(texture1,offset1).xyz ;
vec3 tex2 = texture2D(texture1, offset2).xyz ;
vec3 mixCol = mix( tex1, tex2, multiplier );
vec4 fragColor = vec4(mixCol, 1.0);
if(fragColor.a == 0.0)
discard;
gl_FragColor = fragColor;
}
Explanation:
Since I am having the vertical texture of three different type I make my offset into y direction 0.3333. Because texture is read from [0,1]. I have extended this code same for the horizontal direction.
If some one going to make this dynamic then instead of hard coded we can pass the 0.3333 as the calculate one taking the inspiration form link.

Shadow artifacts in opengl

I am trying to render an object and two lights, one of the lights cast shadows. Everything works ok but I noticed that there are some obvious artifacts, as shown in the below image, some shadows seem to overflow to bright areas.
Below is the shaders to render depth information into a framebuffer
<script id="shadow-shader-vertex" type="x-shader/x-vertex">
attribute vec4 aVertexPosition;
uniform mat4 uObjMVP;
void main() {
gl_Position = uObjMVP * aVertexPosition;
}
</script>
<script id="shadow-shader-fragment" type="x-shader/x-vertex">
precision mediump float;
void main() {
//pack gl_FragCoord.z
const vec4 bitShift = vec4(1.0, 256.0, 256.0 * 256.0, 256.0 * 256.0 * 256.0);
const vec4 bitMask = vec4(1.0/256.0, 1.0/256.0, 1.0/256.0, 0.0);
vec4 rgbaDepth = fract(gl_FragCoord.z * bitShift);
rgbaDepth -= rgbaDepth.gbaa * bitMask;
gl_FragColor = rgbaDepth;
}
</script>
In the above shaders, uObjMVP is the MVP matrix used when looking from the position of the light that cast shadow (the warm light, the cold light does not cast shadow)
And here are the shaders to draw everything:
<script id="shader-vertex" type="x-shader/x-vertex">
//position of a vertex.
attribute vec4 aVertexPosition;
//vertex normal.
attribute vec3 aNormal;
//mvp matrix
uniform mat4 uObjMVP;
uniform mat3 uNormalMV;
//shadow mvp matrix
uniform mat4 uShadowMVP;
//interplate normals
varying vec3 vNormal;
//for shadow calculation
varying vec4 vShadowPositionFromLight;
void main() {
gl_Position = uObjMVP * aVertexPosition;
//convert normal direction from object space to view space
vNormal = uNormalMV * aNormal;
vShadowPositionFromLight = uShadowMVP * aVertexPosition;
}
</script>
<script id="shader-fragment" type="x-shader/x-fragment">
precision mediump float;
uniform sampler2D uShadowMap;
varying vec3 vNormal;
varying vec4 vShadowPositionFromLight;
struct baseColor {
vec3 ambient;
vec3 diffuse;
};
struct directLight {
vec3 direction;
vec3 color;
};
baseColor mysObjBaseColor = baseColor(
vec3(1.0, 1.0, 1.0),
vec3(1.0, 1.0, 1.0)
);
directLight warmLight = directLight(
normalize(vec3(-83.064, -1.99, -173.467)),
vec3(0.831, 0.976, 0.243)
);
directLight coldLight = directLight(
normalize(vec3(37.889, 47.864, -207.187)),
vec3(0.196, 0.361, 0.608)
);
vec3 ambientLightColor = vec3(0.3, 0.3, 0.3);
float unpackDepth(const in vec4 rgbaDepth) {
const vec4 bitShift = vec4(1.0, 1.0/256.0, 1.0/(256.0*256.0), 1.0/(256.0*256.0*256.0));
float depth = dot(rgbaDepth, bitShift);
return depth;
}
float calVisibility() {
vec3 shadowCoord = (vShadowPositionFromLight.xyz/vShadowPositionFromLight.w)/2.0 + 0.5;
float depth = unpackDepth(texture2D(uShadowMap, shadowCoord.xy));
return (shadowCoord.z > depth + 0.005) ? 0.4 : 1.0;
}
vec3 calAmbientLight(){
return ambientLightColor * mysObjBaseColor.ambient;
}
vec3 calDiffuseLight(const in directLight light, const in float visibility){
vec3 inverseLightDir = light.direction * -1.0;
float dot = max(dot(inverseLightDir, normalize(vNormal)), 0.0);
return light.color * mysObjBaseColor.diffuse * dot * visibility;
}
void main() {
vec3 ambientLight = calAmbientLight();
float visibility = calVisibility();
vec3 warmDiffuseLight = calDiffuseLight(warmLight, visibility);
// cold light does not cast shadow and hence visilibility is always 1.0
vec3 coldDiffuseLight = calDiffuseLight(coldLight, 1.0);
gl_FragColor = vec4(coldDiffuseLight + warmDiffuseLight + ambientLight, 1.0);
}
</script>
If I simply draw the depth information out on to the canvas,
void main() {
// vec3 ambientLight = calAmbientLight();
// float visibility = calVisibility();
// vec3 warmDiffuseLight = calDiffuseLight(warmLight, visibility);
// // cold light does not cast shadow and hence visilibility is always 1.0
// vec3 coldDiffuseLight = calDiffuseLight(coldLight, 1.0);
// gl_FragColor = vec4(coldDiffuseLight + warmDiffuseLight + ambientLight, 1.0);
vec3 shadowCoord = (vShadowPositionFromLight.xyz/vShadowPositionFromLight.w)/2.0 + 0.5;
gl_FragColor = vec4(unpackDepth(texture2D(uShadowMap, shadowCoord.xy)), 0.0, 0.0, 1.0);
}
I would get this image
Thanks in advance.

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