Some fun effects shaders for the GLSLShader module

[Magic]

EDIT: In Magic 1.6, many of the effects below are now included as standalone modules in the main installation.
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Here are a few shader effects that work with the GLSLShader module. I created some of them myself, and I edited the others (from http://shadertoy.com and other places).

Make sure you hook up an input to the GLSLShader module to use them.

I'll update this post as I find more good ones. And feel free to add your own!

See post below for ChromaKey instructions.
And there's another (potentially better) ChromaKey later in this topic: http://magicmusicvisuals.com/forums/vie ... rt=10#p805

Also check out my Alpha Mask shader: http://magicmusicvisuals.com/forums/vie ... ?f=3&t=146
And my FadeMix shader: http://magicmusicvisuals.com/forums/vie ... p=711#p711

Sorted newest to oldest:

[Ranya]

Thanks, keep em coming.

[Sadler]

The SmudgeBlur doesn't seem to work for me.

SmudgeBlur.jpg (89.56 KiB) Viewed 420436 times

The other two work well though, as do many GLSL shaders I've tried.

[Magic]

Hmm, that's weird. What kind of graphics card do you have? Perhaps try updating the driver?

[Terry Payman]

The SmudgeBlur doesn't seem to work for me...

Nor me. Tried two Win 7-64 systems.
NVIDIA GTX 580 & GT 610 Cards. Drivers 340.52 originally. Update to latest 344.65 made no difference.

[Magic]

Ok, it might be due to a bug in the original code. Strange. Anyway I fixed it and uploaded it again -- try it and let me know.

[Terry Payman]

...-- try it and let me know.

Fixed!
Nice painterly effect when fed from the default shader. Goldwaves shader shows the effect very clearly. Thanks Eric.

[Sadler]

Yes, fixed for me too - assuming this is the intended effect...

SmudgeBlur2.jpg (79.06 KiB) Viewed 420428 times

[Magic]

That looks right . Cool.

Btw, for that shader you can adjust the X Param to change blur amount.

[Magic]

I just added a Chroma Key shader (download link in first post). The code is based on Brad Larson's framework:
https://github.com/BradLarson/GPUImage/ ... eyFilter.m

He has a bunch of nice ones so I might add more later.

Because the Chroma Key requires an input color, but the GLSLShader module doesn't support one yet, you have to do something a bit convoluted. The second input has to be a solid color which represents the color to remove, such as a Polygon with a Color module :

ChromaKey.jpg (112.57 KiB) Viewed 420419 times

The X Param is "threshold sensitivity" and the Y Param is "smoothing". I recommend you start with values of .2 for each. In the above example you can see that it removes blue from the default shader.

[Terry Payman]

Many thanks for looking at Chroma Key Eric. Very useful!

..Because the Chroma Key requires an input color... you have to do something a bit convoluted. The second input has to be a solid color which represents the color to remove, such as a Polygon with a Color module ...

For green-screen work I find it's easier to be able to tune the hue of the reference color rather than mix RGB.
I've just discovered your HueSaturation module with Lightness = 1 seems to work very well for this purpose (with no input needed). Previously I have used Resolume Avenue's AVFFGLSolidColor which again offers hue control.

BTW I seem to get slightly better keying using casty's Shadertoy "Vlahos chroma key" https://www.shadertoy.com/view/MsS3DW. This seems to totally eliminate any green fringing without impacting the brightness of the foreground object.

Regretfully I don't understand the code for either approach, but it would be awesome if you could devise a hybrid.

[Magic]

it would be awesome if you could devise a hybrid.

I'll try. Doing a quick test, the Shadertoy one seems to work well with the provided video's green color, but when I use a different video or image, and try to match the color, it doesn't work as well. It might be optimized for that particular green.

[Terry Payman]

.. It might be optimized for that particular green.

Indeed! Hard coded as far as I can see, the shader's two inputs being foreground and background images.
It would benefit greatly from the facilities you provided for your Larson-based shader; a reference color input together with two "tuning" parameters.

From experiment, I think perhaps the reference threshold adjustment can be provided by appropriate choice of hue/sat/brightness of the reference input.
If that was the case then the two tuning parameters could perhaps be "sharpness/smoothing" of the transition, and some "erosion" control of the foreground.

If you compiled your own dedicated shader there are a few other controls that are commonly provided.

[Magic]

What I meant is that if even I change the hard-coded settings to make them configurable with inputs and parameters (as I did with one I originally provided), it doesn't seem to work any better. At least with the reference images I'm testing. Can you share something you're testing with?

[Terry Payman]

...Can you share something you're testing with?

Sorry Eric. I should have anticipated that you would do a thorough re-casting .

I grabbed a frame from some greenscreen footage I shot for a short film:

2v9t7o5.jpg (143.23 KiB) Viewed 419081 times

- compare especially the DJ's hair, bottom centre.

- and here's another I found on the web. Turns out to be a grab from some Shutterstock footage http://stock-clip.com/video/3214525-zebra-chroma-key

5ey5bm.jpg (7.33 KiB) Viewed 419081 times

- very clean outline with casty's keyer, even with this very low-res image.

Having done extensive further tests, I confirm my original findings. Even if your version of casty's keyer works only for green, it would be very useful for greenscreen work! I would welcome the opportunity to try it!

[Magic]

Ok, thanks Terry. I'll work on this a bit and see what I can come up with.

[Terry Payman]

I'll work on this a bit and see what I can come up with.

Much appreciated. Many thanks Eric!

[Magic]

Try this Terry. I was able to get it to look pretty good on both the zebra and the DJ.

X Param is adjustable.

ChromaKey2.txt

(898 Bytes) Downloaded 10620 times

[Terry Payman]

... I was able to get it to look pretty good on both the zebra and the DJ..

Me too!
Excellent control of transition and despill!

Works equally well for blue-screen with c.b & c.g interchanged (5 locations total) in the getAlpha & despill subroutines.

Hugely helpful! Very many thanks Eric!

[BaconMKII]

Thanks for these! I had been scratching my head trying to do some kind of chromakey effect with the Resolume plugins without any success.