Values, coordinates, pipet, renderer

Hej, it looks like I don`t get something about values and resolution in vvvv.

I´m working with Pipet right now. I know, that that the coordinates are 0 - 1 not -1 - 1 as vvvv usually uses.
So I guess, if I want to put the Pipet in the middle of something (screen, renderer etc) I have to use coordinates x=0,5; y=0,5. Is that right?

But my problem is if I want to get RGB-values (with Pipet) from VideoTexture or from DX9Texture, than I get different results!!! I mean, the source is the same.

I think, the problem is: if I use the texture for Renderer(EX9) , the Renderer(EX9) shows it smaller. So I suppose, I have to scale the value. But how do I know the proportion?

Does somebody know what I mean?

I have actually a very simple task: i have to track my webcam. I need an overage RGB-value of each frame. But im not sure about the parameter that I use. Also pipet connected to DX9Texture doesnt work the same way.

The second task is to track the overage RGB-value of my screen. And here Im also not sure about my parameter. I dont know how to controll the result.I`m trying since hours, but I´m really not sure if I work correctly.

So, here is the patch. It`s easier to understand.

pipet_webcam_screen_test-1.v4p (40.1 kB)

hi, the size of the rendered texture depends on the size of the renderer. you can set that either with the backbuffer size setting or the width/heigth settings of the DX9Texture (use the inspector, ctrl+i).

pipet_webcam_screen_test-1.v4p (43.3 kB)

hi juliett,
-first center of a screen is 0/0.
0.5 / 0.5 will be the right low corner of your renderer

-pipete is set first at one position ( 0 0 )
and secondlywidth and height are its beam ! it means that its return the average value from all the pixel in the width/eight you give;
so if you set to 1px by 1px its range, it should be better than 640x480 (average value of all the image).

by the way it s a beautifull and clear patch ! ;-P

@ karistouf:

i begin from the end:

First of all thanks, it`s nice to hear. I´m just getting started, so I need really a lot of time for these easy patches.

Second: thats what I need - an average value of the **whole** screen/webcam-picture. But it cahnges every second, so it´s variable. But I wasnt sure about width and height values of Pipet. If these are pixels or something else.

And about coordinates: Check this. Than if you have a look to the help-file of Pipet you will see: “note that the coordinates in texture space have to specified like this: 0/0 - top left; 1/1 - bottom right”

Also have a look at the following patch (see attach) and try it out - than you see what I mean.

So “first center of a screen is 0. 0.5 / 0.5 will be the right low corner of your rendrer” seems to be wrong.

@ tonfilm:

Thanks I got it (I think so…). I`ll try it out.


Maus_Pipette_Screenshot_by_Juliett.v4p (11.0 kB)

ok… i was wrong on all the line ! sorry sorry sorry …
didn t know about this pipet coordonate ( rather strange)

if you experience values differences between DX9, renderers screenshots,ask to devvvv’s…
surely more a trouble of rounding values form one box to the other …

you can also try to smooth the relative difference with the IIR patch, wich is quite nice when you want to smooth something…

but after taking a while inside your user page i supposed that you are preparing something precise ( plastic installation ?)…

IIR (Animation).v4p (5.9 kB)

Its simply alpha at zero. So, thats why you can’t see a thing. ;D

Pipet and Alpha might be of interest for you. Its not too easy too understand that color and alpha stuff - as I experienced either.

Maus_Pipette_Screenshot_by_Juliett2.v4p (12.0 kB)

@ karistouf:

hm, my page is just a box with links. So I dont have a chance to forget the most important things. Otherwise ill never find them again…

No plastic, just some control, some light, some RGB. But it has to be precise.

Thanks for patch. Right now I dont have any brain lost to understand, why do I need it. But ill try to borrow some brains and some time.

@ frank:

Thanks! I wouldn`t know.
But you know, there is a strange thing: I see a thing. I mean, my original patch and the modified one looks the same (I mean, i see colours in both patches).

There is another strange thing: if I open my Patch, the left dobble-klick of my mouse stops to work. The patch works. But I cant use the dobbelklick to open a file or direction somewhere in my system... I dont understand it. Does somebody have the same “troubles”?


hi juliette, IIR is a good way to smooth value.
for example if you use a webcam, and people coming inside, and you have 3 differents ways to make pipet ( cam / dx9text / snapshot) in your project, this could help to smooth the difference between the values (if for example you make projection of the 3 results side by side).
don t know if i m clear ( glups glops). otherwise, never mind.