Remove the space between ISADORA_FLOAT_PARAM and (

So the second one ;) The first one is your example

// ISADORA_FLOAT_PARAM (noise_level, noil, 0.0, 1.0, 0.5, "This is the text that helps");

// ISADORA_FLOAT_PARAM(noise_level, noil, 0.0, 1.0, 0.5, "This is the text that helps");

uniform float noise_level;
// ISADORA_FLOAT_PARAM (noise_level, noil, 0.0, 1.0, 0.5, "dit is de text  die helpt");
uniform float dark_factor;
// ISADORA_FLOAT_PARAM (dark_factor, dkfa, 0.0, 1.0, 0.5, "dit is wat het doet");
// #define NOISE_LEVEL 0.25
// #define DARKEN_FACTOR 0.125
#define DENOMINATOR vec2(213, 5.53)
#define NEG_X vec2(-1.0, 1.0)
#define NEG_Y vec2(1.0, -1.0)
#define GLITCH_OFFSET_1 vec2(32.05, 236.0)
#define GLITCH_OFFSET_2 vec2(-62.05, -36.0)
float rand(vec2 co)
{
 return fract(sin(dot(co.xy, vec2(12.9898, 78.233))) * 43758.5453);
}
void mainImage(out vec4 fragColor, in vec2 fragCoord)
{
 vec2 uv = fragCoord.xy / iResolution.xy;
    
    // Scanline desync
 if (mod(iTime, 2.0) > 1.9)
 uv.x += cos(iTime * 10.0 + uv.y * 1000.0) * 0.01;
    
    // Pixelate glitch 1
    if (mod(iTime, 4.0) > 3.0)
 uv = floor(uv * 32.0) / 32.0;
    // Pixelate glitch 2
 if (mod(iTime, 5.0) > 3.75)
    uv += 1.0 / 64.0 * (2.0 * vec2(
            rand(floor(uv * 32.0) + GLITCH_OFFSET_1),
            rand(floor(uv.y * 32.0) + GLITCH_OFFSET_2)) - 1.0);
fragColor = texture(iChannel0, uv);
    fragColor.rgb
        += noise_level
        * vec3(rand(iTime + fragCoord / DENOMINATOR * NEG_X),
               rand(iTime - fragCoord / DENOMINATOR * NEG_Y),
               rand(iTime + fragCoord / DENOMINATOR))
        - dark_factor;
        
     
 
}

massive thumbs up!

Thank you for letting me know. I will make the instructions clearer.

Best Wishes,
Mark

From what I see above, the path in your downloads folder is something like

C:\Users\YOUR_USER_FOLDER_NAME\Downloads\ISF-Files-Master (1)\ISF Files master

that won't work. (The underlined and bold part is wrong.) It must be exactly:

C:\Users\YOUR_USER_FOLDER_NAME\Downloads\ISF-Files-Master

Best Wishes,
Mark

Did you download the ISF files to your downloads folder?

1) Go to the ISF Files github
2) Click the "Clone or Download" button and choose "Download ZIP"
3) After the download completes, verify you now have a file called ISF-Files-master.zip in your download folders.
4) Right-click the .zip file and extract the contents of the .zip so that you see a folder called ISF-Files-master in your downloads folder. (Here are instructions on how to extract a zip file to a folder.)

The script if the ISF-Files-master folder is in your downloads folder.

Best Wishes,
Mark

@mark sorry its here.....ony recently entered the forums so finding my feet....

I've included the command window response for your perusal. 

 Where? I don' see it.

Best Wishes,
Mark

Regards

Gavin

Well, one of the problems is that Isadora is going to scale this image up to the stage size, and then it's going to get blurry because of the scaling.

If you need the image to stay really low res, set the stage size to something low in the Stage Setup editor, and then use the "Capture Stage to Picture" actor to grab a picture at that resolution.You can then scale it up in an image editing program. Here's a patch with the stage set to a custom size of 128x72 as shown below.

Here's an example snap of the stage using my webcam.

Same image scaled up in Photoshop using Nearest Neighbor resampling to preserve the hard edges:

And a black and white version...

Maybe that helps?

Here's the patch: glsl dithering small stage.izz

Best Wishes,
Mark

[NOTE: my reply is for Sam, but this info is useful for all! Please read. ;-) ]

OK, I think I've gotten some dithers worked out for you.

First, regarding the ShaderToy code for Dither Webcam:

Remember what I said in the tutorial regarding looking at the iChannel0, iChannel1, inputs, etc. Look at this part of the page:

The webcam is video input 1 (iChannel0) but it needs a texture for video input 2, as seen in the iChannel1 input. The problem with ShaderToy is that it is not very apparent which texture has been chosen because it's scaling and anti-aliasing it in the preview. :-(

In the end, I determined it was the texture called Bayer which is an 8x8 grid of greyscale values. (Bayer is a technique used for dithering, that was my clue.)

But then the question becomes, how do you get that texture? At the moment, the site ShaderToy Unofficial has a page that gives links to the textures under the section ShaderToy Media Files. Hopefully the image I've circled looks familiar from above:

So I clicked that and downloaded it. If you provide that as the second input, the dithering works.

I also worked around the error in the ShaderToy 4x4 Bayer Dithering shader. It needs to do an integer modulo operation (the '%' operator) which macOS doesn't want to do. But I created a function to peform the modulo called "modulo" which you'll see in the code.

In addition, I added a 'color amt' parameter to this shader to allow you to see the dithered color (the default for the ShaderToy) or a black and white version.

For both of these shaders, I made three scenes: one at the native resolution of the camera, one scaled to 640x360, and one scaled to 320x180. This will change the look of the final image, as smaller images may give you more of what you were hoping for.

I also made three versions of the bayer image png for the Dither Webcam patches. The 8x8 one I downloaded from ShaderToy Unofficial didn't look as good as a 96x96 pixel image I got from ShaderToy itself. The patches are set to use the 96x96 pixel version of the 8x8 matrix, but you can experiment with the 8x8 pixel, 96x96pixel, and 192x192pixel matrix images to see what you like best.

Let me know what you find and if this gives you what you were looking for.

glsl dithering.zip

Best WIshes,
Mark

thanks for the code - it compiles, but im still having the same issues regards resolution (see images) - what does it look like for you?

Maybe you need to connect both video inputs... did you do that?

Best Wishes,
Mark

thanks for the code - it compiles, but im still having the same issues regards resolution (see images) - what does it look like for you?

Ditter webcam 

https://gist.github.com/Juriaa...

Regarding your 4x4 Bayer Dithering, the code works fine as is. What operation system are you on / what version of Isadora ?

Hi Mark - thankyou for the session. It's a complex area to get my head around but I grasped some of it - im sure the video will be rewatched!

If anyone can help me in my lo-res quest  - 

I am trying to find a dither shader and get it to work (I talked about this a year or so ago on the forum - but I'm still no wiser!) - it either looks too high res or completely anti aliased. I've tried changing resolution in video preferences / turning shader full frame anti aliasing off, and changing resolution in the shader.

Is there some hidden thing I need to switch? (@Maxime - you seemed to have more success with the Obra Dinn shader)

I've made a list below of examples I've used, and errors (for those that don't compile) - if anyone can get a nice crisp dither shader running in izzy please let me know - that would be awesome!

Examples that compile image is too high resolution / anti aliasing

• 1-Bit Waves - https://www.shadertoy.com/view/WtsXW2

• Obra Dinn dither - https://www.shadertoy.com/view/4sySzw

• Classic Mac floyd-steinberg-ish - https://www.shadertoy.com/view/4sjGRD

Examples that give errors and won't compile:

• Dither Webcam - https://www.shadertoy.com/view/wsjSRd

Error:

FRAG ERROR: 0:20: Invalid call of undeclared identifier 'round'

• Bayer maxtrix dithering explorer  - https://www.shadertoy.com/view/WtjSzm

Error:

syntax error: Array size must appear after variable name

• 4x4 Bayer Dithering - https://www.shadertoy.com/view/WstXR8

Error:

FRAG ERROR: 0:29: '%' does not operate on 'int' and 'int'
FRAG ERROR: 0:29: '%' does not operate on 'int' and 'int'
FRAG ERROR: 0:37: Use of undeclared identifier 'bayerValue'
FRAG ERROR: 0:38: Use of undeclared identifier 'bayerValue'
FRAG ERROR: 0:39: Use of undeclared identifier 'bayerValue'

Could you share the GLSL code that you put inside your code window ? Upload it to Gist / Pastebin or use a Code block here on the forum. Then we can take a look with ya :)

Although I'm not a coder, I think I could follow most of what you demonstrated.

Sadly my custom parameters/inputs were not working in any of the shaders I tried them on (not sure if my screenshots are uploading..)

When typing the code, no compile errors, but also no changes to the actor after compile/ok.

When I copy pasted the text, from the chat:

uniform float dark_factor;
// ISADORA_FLOAT_PARAM(dark_factor, dkfa, 0.0, 1.0, 0.125, "This is the amount of darkness.");

I get messages like :

FRAG ERROR: 0:14: '<' : syntax error: syntax error<a href="/assets/uploads/files/1588182227804-screenshot-2020-04-29-at-19.16.00-resized.png"></a>

*** NOTE *** The recording of the livestream is offline for a few hours while we make an edit... it will be online again by Thursday Morning, Apr 30th. *****

Watch the live stream (also good for later viewing)

See you in a little bit! ;-)

Best Wishes,
Mark