Need help with a script :-)

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function prepare()    -- This function is called once,    -- before the rendering begins.    -- Use it for querying non-mapped    -- inputs and precalculation.    opa = get_slider_input(OPACITY)    count = get_intslider_input(REPEAT)    hdr = false    if(get_checkbox_input(REVERSE)) then       rev = true    else       rev = false    end    if(get_checkbox_input(FADE)) then       fade = true    else       fade = false    end end; function get_sample(x, y)    -- Image generation code goes here.    dir = get_sample_grayscale(x, y, DIRECTION)    spacing = get_sample_grayscale(x, y, SPACING)    ofx = get_sample_grayscale(x, y, OFFX)    ofy = get_sample_grayscale(x, y, OFFY)    r, g, b, a = get_sample_map(x + ofx, y + ofx, IMAGE)    ofx = get_sample_grayscale(x, y, OFFX)    ofy = get_sample_grayscale(x, y, OFFY)    local opacity = opa    density = 1    i = 0    if fade then       fad = 0.1    else       fad = 0    end    while (i < count ) do       ri,gi,bi,ai = get_sample_map((x  * density )+ ofx , (  y  * density)+ ofy, IMAGE)       r, g, b, a = blend_normal   (r, g, b, a, ri, gi, bi, ai, opacity - fad, hdr)       if (rev)   then             density = density + spacing       else          density = density - spacing       end       i = i + 1       if fade then       fad = fad + 0.1       end    end;    return r, g, b, a end;

try

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... ri,gi,bi,ai = get_sample_map((x - 0.5)  * density + ofx + 0.5, (y - 0.5)  * density + ofy + 0.5, IMAGE) ...

Works like a charm now

The image was done with my new filter Bubble fun, thats why you can´t reproduce it with the script
And the direction slider currently does nothing, it was left over from trying to figure out how to change the stacking direction
I want to make some more changes to the script, will post an update then.

while the stacking part works now, and I can offset it, or have it centered now, I´m still having issues with the script.

Above certain values for repeating and spacing it starts multiplying the whole stack instead the image, which leads to a kaleidoscope like effect. While that is interesting and fun, it´s not what I really wanted. And I have no clue why

Sphinx, or anyone else, do you have any idea why that happens and could you try to explain it to me?

Yeah, I think that´s exactly the problem. I had a play with the scale component and it does the same thing. I tricked it by putting a frame around the scaled imaged, but that has it´s limits too.

I hope they add some components for effects like this in the future.
Juggling 50 components just for one simple effect is annoying.

I can do this in Photoshop in like 30 seconds by just duplicating and scaling the layers, and record an action for future use. It´s even faster than waiting for FF to render it
No need to create a filter for it I guess.
Apart from the pleasure to create something for other people to have fun with

Sorry, didn't understand the question...

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Sorry, didn't understand the question...

ri,gi,bi,ai = get_sample_map(x,y IMAGE)

Adding or subtracting from x and y offsets the image, multiplying scales it. As far as I could figure it out.
How can you add a rotation? For example the image around its center, or the duplicates in my script around the center.
Dunno if that makes it any clearer.

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...BUT what I think would be interesting is to be able to customize and define the effect in many different ways and to be able to multiply the image as required and as many or few as you want, and change the orientation and offset and some other settings that would not be possible to make in a Photoshop Action.

I agree. That was the reason I started creating this script anyway, to have a customizable component that does this which we can use in our filters.

I managed to get rid of the unwanted repetitions. It was the spacing settings that caused it. It can only be between 0.01 and 0.04 to work, so I just set it to 0.04 and got rid of the input. Also apparently 30 is the maximum for repetitions for some reason.
Still got some things to fix, but here is an updated version for now. I added in some example shapes, play around with it and try out adding your own

stacking mapscript 2.ffxml

Looking good!

Well the spacing setting is fixed, but you could just give your original image more space around it to increase the spacing.

lifesaver with transparency fed into kaleidoscope

Ok, need help again:

Lets say I have a free ellipse. Now I want that to always be for example in the center of the image, no matter what size it is.
How can I convert the OUTPUT_HEIGHT, OUTPUT_WIDTH values to values the offset wants?

Edit: this is what I got so far

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function prepare()     end; function get_sample(x, y) d = ((OUTPUT_HEIGHT/OUTPUT_WIDTH)/2 - 0.5 ) return d, d, d, 1 end;

My problem is that I can get it to work either if the image is higher than wide, or wider than high, but not at the same time.

You probably need an IF statement that does a different calculation depending on whether OUTPUT_HEIGHT is bigger or smaller than OUTPUT_WIDTH.

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ThreeDee wrote: You probably need an IF statement that does a different calculation depending on whether OUTPUT_HEIGHT is bigger or smaller than OUTPUT_WIDTH.

Doh! Simple! Why didn´t I think of that?! >.< Thanks Threedee, you´re a star!

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ThreeDee wrote: Sine, Cosine, ArcSine and ArcCosine can be used to get linear coordinates converted to rotation angles and vice versa. You have to calculate them from the center point (.5,.5) to get the rotation around center.

Too much Math in one sentence (no offence ment). But thanks Good to know anyway, even tho I have no clue how to calculate that :S

Oh wow, thx Indigo! You´re a star aswell!
I´ll give it a try when I´m finished with my other stuff!!
Not sure about the homework, but I think I can do a simple rotation based on your explanation.