amandaghassaei / gpu-io Goto Github PK

Hello again Amanda,

I am trying to change the default black background color without success.

We can also refer to this example in the further code:
https://openprocessing.org/sketch/1760726

I tried to change the render fragment shader from this:

in vec2 v_uv;
uniform sampler2D u_trail;
uniform float u_scale;
out vec4 out_state;
void main() {
	out_state = vec4(texture(u_trail, v_uv).xyz * u_scale, 1);
}

To this:

in vec2 v_uv;
uniform sampler2D u_trail;
uniform float u_scale;
out vec4 out_state;
float luma(vec3 color) {
	return dot(color, vec3(0.299, 0.587, 0.114));
}
void main() {
	vec3 trailColor = texture(u_trail, v_uv).xyz * u_scale;
	float brightness = luma(trailColor );
	vec3 backgroundColor = vec3(1.0, 0.0, 0.0);
	vec3 mixedColor = mix(backgroundColor, trailColor , brightness);
	out_state = vec4(vec3(mixedColor), 1);
}

The result is almost there, but the mixedColor borders are not smooth.

Thank you once again,
Carlos

Wondering if anyone has tried reading data from gpu-io framebuffers to a pixel buffer, and if so how did it go?

I'm considering trying this. I think it could potentially simplify the process of using data computed with gpu-io as regular old uniform buffer/vertex buffer data, as an alternative to transform feedback, and to extra texture sampling. That said, I'm unsure about performance, so will need to experiment.

If it works it'd be cool to have a little API for it, especially if it could be used with THREE.js buffers in the same way as the textures can be shared.

(by the way, this library is awesome, I tried like 5 different WebGL GPGPU libraries before settling on this one and it's been working out great)

Hi Amanda,

I am trying to update the array of colors attached to the GPULayer after initialization.

I am referring to your example available here:
https://openprocessing.org/sketch/1760726

I already tried to invoke other methods like:
particlesColor.setFromArray(colors);

But the values are not updated.

I also tried different combinations of invoking step method by the program.

Cheers,
Carlos

README.md file has a TODO note to add an example of working with 3D textures, it would be nice to have.

• Show how to store 3D data in a 1D array.
• Show how to work with the 3D texture in the shader, including how to access the texture data using 3D coordinates

I am a little confused about when the canvas is cleared in a multi-step program. How does one disable canvas clearing, for instance?