Okay, I read @Ignatz’s Ebook on Shaders and I nearly perfected a cloud shader I’ve been working on, but here’s the problem;
It only works in the following circumstances:
- the "uniform sampler2D texture; is set to a background image like SpaceCute:Background, and
- When the keyboard is up, limiting the visible space of the shader.
Here’s the Vertex:
//
// CloudShader.vsh
// created with Shaderific
//
attribute vec4 position;
attribute vec3 normal;
uniform mat4 modelViewProjectionMatrix;
uniform mat4 modelViewMatrix;
uniform mat3 normalMatrix;
uniform float time;
varying vec3 eyespaceNormal;
varying vec4 eyespacePosition;
varying vec3 noiseVector;
void main(void)
{
vec3 translation = vec3(1.0, 1.0, 1.0) * time / 20.0;
noiseVector = position.xyz + translation;
eyespaceNormal = normalMatrix * normal;
eyespacePosition = modelViewMatrix * position;
gl_Position = modelViewProjectionMatrix * position;
}
Here’s the Fragment:
//
// CloudShader.fsh
//
//
//
// Description : Array and textureless GLSL 2D/3D/4D simplex
// noise functions.
// Author : Original Heat Shader By: Ian McEwan
// Cloud Conversion By: Austin Wiltse/CodeaNoob
//
precision highp float;
precision highp int;
uniform lowp sampler2D texture;
varying vec3 eyespaceNormal;
varying vec4 eyespacePosition;
varying vec3 noiseVector;
uniform vec4 materialDiffuseColor0;
uniform vec4 materialDiffuseColor;
vec3 mod289(vec3 x) {
return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec4 mod289(vec4 x) {
return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec4 permute(vec4 x) {
return mod289(((x*34.0)+1.0)*x);
}
vec4 taylorInvSqrt(vec4 r)
{
return 1.79284291400159 - 0.85373472095314 * r;
}
float snoise(vec3 v)
{
const vec2 C = vec2(1.0/6.0, 1.0/3.0) ;
const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);
// First corner
vec3 i = floor(v + dot(v, C.yyy) );
vec3 x0 = v - i + dot(i, C.xxx) ;
// Other corners
vec3 g = step(x0.yzx, x0.xyz);
vec3 l = 1.0 - g;
vec3 i1 = min( g.xyz, l.zxy );
vec3 i2 = max( g.xyz, l.zxy );
// x0 = x0 - 0.0 + 0.0 * C.xxx;
// x1 = x0 - i1 + 1.0 * C.xxx;
// x2 = x0 - i2 + 2.0 * C.xxx;
// x3 = x0 - 1.0 + 3.0 * C.xxx;
vec3 x1 = x0 - i1 + C.xxx;
vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
vec3 x3 = x0 - D.yyy; // -1.0+3.0*C.x = -0.5 = -D.y
// Permutations
i = mod289(i);
vec4 p = permute( permute( permute(
i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
+ i.y + vec4(0.0, i1.y, i2.y, 1.0 ))
+ i.x + vec4(0.0, i1.x, i2.x, 1.0 ));
// Gradients: 7x7 points over a square, mapped onto an octahedron.
// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
float n_ = 0.142857142857; // 1.0/7.0
vec3 ns = n_ * D.wyz - D.xzx;
vec4 j = p - 49.0 * floor(p * ns.z * ns.z); // mod(p,7*7)
vec4 x_ = floor(j * ns.z);
vec4 y_ = floor(j - 7.0 * x_ ); // mod(j,N)
vec4 x = x_ *ns.x + ns.yyyy;
vec4 y = y_ *ns.x + ns.yyyy;
vec4 h = 1.0 - abs(x) - abs(y);
vec4 b0 = vec4( x.xy, y.xy );
vec4 b1 = vec4( x.zw, y.zw );
//vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
vec4 s0 = floor(b0)*2.0 + 1.0;
vec4 s1 = floor(b1)*2.0 + 1.0;
vec4 sh = -step(h, vec4(0.0));
vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;
vec3 p0 = vec3(a0.xy,h.x);
vec3 p1 = vec3(a0.zw,h.y);
vec3 p2 = vec3(a1.xy,h.z);
vec3 p3 = vec3(a1.zw,h.w);
//Normalise gradients
vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
p0 *= norm.x;
p1 *= norm.y;
p2 *= norm.z;
p3 *= norm.w;
// Mix final noise value
vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
m = m * m;
return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1),
dot(p2,x2), dot(p3,x3) ) );
}
void main(void)
{
float intensity = (snoise(noiseVector * 5.0) +
0.5 * snoise(noiseVector * 10.0) +
0.25 * snoise(noiseVector * 20.0) + 1.75) / 3.5;
float exponent = intensity - 0.35;
if (exponent < 0.0)
exponent = 0.0;
intensity = 1.0 - pow(0.1, exponent);
float attenuation = dot(eyespaceNormal, -normalize(eyespacePosition.xyz));
if (attenuation < 0.5)
attenuation = 3.0 - 4.0 * attenuation;
else
attenuation = 1.0;
vec3 color = mix(attenuation * vec3(0.2, 0.2, 0.6), vec3(1.0, 1.0, 1.0), intensity);
gl_FragColor = vec4(color, 1.0);
}
I assume it’s too complicated of a shader to do, but that is whats confusing me! The ripple example shader works, but not a simple cloud one?Also, Please explain to me why It doesn’t move, that’s this shaders one job, otherwise i’d use a sprite.