Shader Code not working !

Programming Questions

koberger

in Programming Questions • 10 months ago

Im trying to port some processing code to shader code to generate a "magic eye" image out of a pattern and a depthmap. The working source code of the processing sketch can be found here: http://kobe.bplaced.net/processing/projekte/magischesAuge/Hai/.

This is the processing source code of the ported shader example:

PShader basic;
PImage hai, pattern;
PGraphics haiGraph, patternGraph;
boolean enabled = true;
void setup() {
size(1260, 600, P2D);
hai = loadImage("hai_grey.png");
pattern = loadImage("hai_pattern.png");
haiGraph = createGraphics(hai.width, hai.height, P2D);
patternGraph = createGraphics(pattern.width, pattern.height, P2D);
basic = loadShader("fragment.glsl");
basic.set("patternSampler", patternGraph);
basic.set("haiSampler", haiGraph);
}
void draw() {
background(40);
haiGraph.beginDraw();
haiGraph.image(hai, 0, 0);
haiGraph.endDraw();
patternGraph.beginDraw();
;
patternGraph.image(pattern, 0, 0);
patternGraph.endDraw();
//int fr=frameCount;
//basic.set("frame", fr);
fill(100);
if (enabled == true) {
shader(basic);
println("shader");
}
image(haiGraph, 0, 0);
println(frameRate);
}
void mousePressed() {
enabled = !enabled;
if (!enabled == true) {
resetShader();
}
}

And here is the Shader:

#ifdef GL_ES
precision mediump float;
precision mediump int;
#endif
uniform sampler2D patternSampler;
uniform sampler2D haiSampler;
varying vec4 vertTexcoord;
void main() {
float sum=0.0;
for (float x = 0.0; x < vertTexcoord.x; x+=0.001) {
vec2 depthCoord = vec2(vertTexcoord.x, vertTexcoord.y);
vec4 depth = texture2D(haiSampler, depthCoord.st).rgba;
sum+=abs(depth.g/2000.0);
}
float vertTexs = mod((vertTexcoord.s)*1200.0,140)/140.0+sum;
vec2 patternCoord = vec2(vertTexs, vertTexcoord.t);
vec4 patternColor = texture2D(patternSampler, patternCoord.st).rgba;
gl_FragColor = patternColor;
}

The pixelshift to generate the impression of depth does not work properly!

Thanks for any suggestions!

Replies(1)

andres

Re: Shader Code not working !

10 months ago

It seems that you want to shader to be applied on the haiGraph image. This means that the shader is a "texture" shader (it operates on textured geometry, in this case the textured rect that results form the image(haiGraph, 0, 0) call. Since you are only providing the fragment shader code, Processing identifies that shader as a texture shader if it finds the "uniform sampler2D textureSampler" string in it... I know this is slightly confusing, and we are currently working to clean-up the uniform/attribute names, and also improve the shader type detection method. For the time being, you should replace

uniform sampler2D haiSampler;

uniform sampler2D textureSampler;

in your shader code. Processing will automatically assign haiGraph to textureSampler, so you don't need to call basic.set("haiSampler", haiGraph) in setup. I hope this helps.

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