# Processing

**URL:** https://discourse.processing.org/c/processing/6.md?no_subcategories=false&page=267

[Latest](https://discourse.processing.org/latest.md) · [Categories](https://discourse.processing.org/categories.md) · [Tags](https://discourse.processing.org/tags.md)

**Page:** 268

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## [Draw line on image?](https://discourse.processing.org/t/draw-line-on-image/14587)

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**Author:** [@darinb](https://discourse.processing.org/u/darinb)\
**Replies:** 12\
**Last updated:** [October 11, 2019, 9:37pm UTC](https://discourse.processing.org/t/draw-line-on-image/14587 "2019-10-11T21:37:53Z")

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This maybe be the most newbie question of the day. :slight\_smile: The boiled down version: I want to display a photograph. Before I display it I want to draw a line, top to bottom, through the image. The line won’t be c…

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## [Analyzing two SoundFile objects at the same time](https://discourse.processing.org/t/analyzing-two-soundfile-objects-at-the-same-time/14616)

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**Author:** [@Brunehilde](https://discourse.processing.org/u/Brunehilde)\
**Replies:** 3\
**Last updated:** [October 11, 2019, 8:25pm UTC](https://discourse.processing.org/t/analyzing-two-soundfile-objects-at-the-same-time/14616 "2019-10-11T20:25:20Z")

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Hi there, I was setting up a test scene to, well, test stuff, when I stumbled across this problem : it would seem that I can’t analyze two SoundFile objects at the same time. I’ve tried with a WhiteNoise and an AudioIn a…

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## [Git Bash and how to get repository with it](https://discourse.processing.org/t/git-bash-and-how-to-get-repository-with-it/14527)

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**Author:** [@mathilde.lavoie](https://discourse.processing.org/u/mathilde.lavoie)\
**Replies:** 1\
**Last updated:** [October 11, 2019, 8:15pm UTC](https://discourse.processing.org/t/git-bash-and-how-to-get-repository-with-it/14527 "2019-10-11T20:15:07Z")

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Hi there can someone explain me how to get a repository from Git Hub and open it in Processing using the application Git Bash, i dont find the answer online. Thanks for the answer!

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## [Rotating vectors around the Y-axis](https://discourse.processing.org/t/rotating-vectors-around-the-y-axis/14613)

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**Author:** [@solub](https://discourse.processing.org/u/solub)\
**Replies:** 1\
**Last updated:** [October 11, 2019, 4:58pm UTC](https://discourse.processing.org/t/rotating-vectors-around-the-y-axis/14613 "2019-10-11T16:58:00Z")

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Dear all, I would need your help to compute the vectors of a 3D curl field. In 2D I used to: create a vector field in 2D place a bunch of points randomly in that field have the vectors pointing to their closest point …

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## [Interactive Light up Grid Game](https://discourse.processing.org/t/interactive-light-up-grid-game/14606)

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**Author:** [@JPG](https://discourse.processing.org/u/JPG)\
**Replies:** 4\
**Last updated:** [October 11, 2019, 3:14pm UTC](https://discourse.processing.org/t/interactive-light-up-grid-game/14606 "2019-10-11T15:14:27Z")

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Hi everyone, The outline of the project is we create a simple 3 x 3 grid of boxes. Then what I want to achieve is a random box will light up and you have to put the mouse in that box. Then another box will light up and …

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## [Unable to use P3D](https://discourse.processing.org/t/unable-to-use-p3d/1873)

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**Author:** [@JohnAo](https://discourse.processing.org/u/JohnAo)\
**Replies:** 6\
**Last updated:** [October 11, 2019, 2:03pm UTC](https://discourse.processing.org/t/unable-to-use-p3d/1873 "2019-10-11T14:03:34Z")

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Everything worked just fine yesterday, but now I cannot even run a simple sketch like this: void setup() { size(200,200,P3D); } void draw() { } When I click “Run”, nothing happens. Please let me know if I can provi…

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## [How To Draw An Image File As PShapes?](https://discourse.processing.org/t/how-to-draw-an-image-file-as-pshapes/14597)

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**Author:** [@XXX](https://discourse.processing.org/u/XXX)\
**Replies:** 9\
**Last updated:** [October 11, 2019, 12:34pm UTC](https://discourse.processing.org/t/how-to-draw-an-image-file-as-pshapes/14597 "2019-10-11T12:34:47Z")

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I would like to draw an image file as PShapes; however, the result is a black canvas. How may I correct this to display the image as PShapes? // Global Variables. PImage img; // Setup. void setup() { // Size of c…

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## [Arduino/Processing Radar](https://discourse.processing.org/t/arduino-processing-radar/14599)

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**Author:** [@WildMan98](https://discourse.processing.org/u/WildMan98)\
**Replies:** 1\
**Last updated:** [October 11, 2019, 11:47am UTC](https://discourse.processing.org/t/arduino-processing-radar/14599 "2019-10-11T11:47:16Z")

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I’m making a Radar with the help of Arduino. However, the processing code shows this error message. RuntimeException: Error opening serial port COM3: Port busy This is my code; import processing.serial.\*; // imports l…

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## [Sketch path is not set](https://discourse.processing.org/t/sketch-path-is-not-set/2279)

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**Author:** [@Rfblock](https://discourse.processing.org/u/Rfblock)\
**Replies:** 5\
**Last updated:** [October 11, 2019, 4:49am UTC](https://discourse.processing.org/t/sketch-path-is-not-set/2279 "2019-10-11T04:49:04Z")

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I’m using the Yahoo Weather Library GitHub - delvedor/YahooWeatherProcessing: Yahoo Weather library for Processing however I get an error whenever i try to create a weather object. My code: import processing.serial…

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## [Adding an Array but gets NullPointException](https://discourse.processing.org/t/adding-an-array-but-gets-nullpointexception/14595)

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**Author:** [@DatSoi](https://discourse.processing.org/u/DatSoi)\
**Replies:** 1\
**Last updated:** [October 11, 2019, 3:48am UTC](https://discourse.processing.org/t/adding-an-array-but-gets-nullpointexception/14595 "2019-10-11T03:48:32Z")

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Hi, so im working on a code where it will track a users face through the OpenCV library. At the moment the code works with a single image and will trace the users face. However when i add an Array to it to add a element …

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## [Audio plays but screen stays black](https://discourse.processing.org/t/audio-plays-but-screen-stays-black/14586)

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**Author:** [@SimonRedfox](https://discourse.processing.org/u/SimonRedfox)\
**Replies:** 1\
**Last updated:** [October 11, 2019, 1:52am UTC](https://discourse.processing.org/t/audio-plays-but-screen-stays-black/14586 "2019-10-11T01:52:20Z")

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Here is my code, the scenario is opened from Arduino button. One button plays 1 and the other 2. The buttons and the printing work good. The screen opens, audio plays but the movie/frames don’t. import processing.serial…

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## [Keyboard controls for multiplayer games](https://discourse.processing.org/t/keyboard-controls-for-multiplayer-games/14580)

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**Author:** [@KowtowToMao](https://discourse.processing.org/u/KowtowToMao)\
**Replies:** 2\
**Last updated:** [October 11, 2019, 12:27am UTC](https://discourse.processing.org/t/keyboard-controls-for-multiplayer-games/14580 "2019-10-11T00:27:19Z")

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I’m trying to make a variant of pong, as well as a tanks game, but I can’t find a good way to make multiplayer work. Advice? Current method in the pong variant is shown below, but it has trouble taking multiple inputs at…

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## [Arduino – Processing – Java](https://discourse.processing.org/t/arduino-processing-java/14581)

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**Author:** [@Jojo43](https://discourse.processing.org/u/Jojo43)\
**Replies:** 1\
**Last updated:** [October 10, 2019, 5:18pm UTC](https://discourse.processing.org/t/arduino-processing-java/14581 "2019-10-10T17:18:00Z")

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I want to reach the values of the counter about processing. My problem is that my Arduino output is X20, and Y20 (step) and I want the output to be displayed on two surfaces One for X and Second Y. String X20 on X and 2…

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## [Transparent images](https://discourse.processing.org/t/transparent-images/3337)

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**Author:** [@ShowStopper](https://discourse.processing.org/u/ShowStopper)\
**Replies:** 8\
**Last updated:** [October 10, 2019, 2:30pm UTC](https://discourse.processing.org/t/transparent-images/3337 "2019-10-10T14:30:34Z")

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Wondering if theres any good way to use transparent images (images that do not have a rectangular border) in processing. I remember being able to do this once before but every time I try it now the image always has a whi…

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## [I can't find this error online](https://discourse.processing.org/t/i-cant-find-this-error-online/14569)

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**Author:** [@SimonRedfox](https://discourse.processing.org/u/SimonRedfox)\
**Replies:** 1\
**Last updated:** [October 10, 2019, 12:02pm UTC](https://discourse.processing.org/t/i-cant-find-this-error-online/14569 "2019-10-10T12:02:41Z")

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\*\* (Processing core video:1627): WARNING \*\*: gstvideo: failed to get framerate property of pad playsink1:audio\_sink This is the error I’m getting for the following codes processing: import processing.serial.\*; import …

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## [Mirror video doodles. ArrayIndexOutOfBoundsException](https://discourse.processing.org/t/mirror-video-doodles-arrayindexoutofboundsexception/14557)

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**Author:** [@elom1213](https://discourse.processing.org/u/elom1213)\
**Replies:** 2\
**Last updated:** [October 10, 2019, 9:17am UTC](https://discourse.processing.org/t/mirror-video-doodles-arrayindexoutofboundsexception/14557 "2019-10-10T09:17:38Z")

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While I’m studying the book ‘Learning processing’, written by Daniel Shiffman, there’s keep error on my code. import processing.video.\*; Capture video; float x; float y; void setup() { size(352, 288); background(2…

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## [Losing saved parts of sketches (tabs)](https://discourse.processing.org/t/losing-saved-parts-of-sketches-tabs/14391)

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**Author:** [@GvB](https://discourse.processing.org/u/GvB)\
**Replies:** 9\
**Last updated:** [October 10, 2019, 9:10am UTC](https://discourse.processing.org/t/losing-saved-parts-of-sketches-tabs/14391 "2019-10-10T09:10:52Z")

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Working on a larger project and having occasional reoccuring problems with saved sketches. They do not seem to save that well to files. My sketch exists of 7 different tabs. Every so often one of these tabs (x.pde) seem…

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## [Problem with setup() loading order, instantiate an object with 'width' and 'height'](https://discourse.processing.org/t/problem-with-setup-loading-order-instantiate-an-object-with-width-and-height/14552)

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**Author:** [@Protos](https://discourse.processing.org/u/Protos)\
**Replies:** 4\
**Last updated:** [October 10, 2019, 8:01am UTC](https://discourse.processing.org/t/problem-with-setup-loading-order-instantiate-an-object-with-width-and-height/14552 "2019-10-10T08:01:53Z")

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Hi, How can I reliably provide width and height to the constructor while creating an object instance. I am constructing a “device object” from a class which is automatically loaded before setup() is executed. In the de…

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## [Can someone help explain this to me?](https://discourse.processing.org/t/can-someone-help-explain-this-to-me/14563)

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**Author:** [@isaacpowwow](https://discourse.processing.org/u/isaacpowwow)\
**Replies:** 1\
**Last updated:** [October 10, 2019, 2:12am UTC](https://discourse.processing.org/t/can-someone-help-explain-this-to-me/14563 "2019-10-10T02:12:54Z")

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void draw(){ stroke(8,65,92); float steps29 = 1026.4 ; int distance29 = 670 ; int floors = 48; float pointAngle = 360.0/floors; int radius = 670; strokeWeight(1.5); for (float angle = 0; angle \< 360.0; angle = ang…

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## [Can I read\_voltage.pde to graph voltage as sound?](https://discourse.processing.org/t/can-i-read-voltage-pde-to-graph-voltage-as-sound/14551)

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**Author:** [@MatthewClark](https://discourse.processing.org/u/MatthewClark)\
**Replies:** 1\
**Last updated:** [October 10, 2019, 12:48am UTC](https://discourse.processing.org/t/can-i-read-voltage-pde-to-graph-voltage-as-sound/14551 "2019-10-10T00:48:16Z")

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Hello, Pretty new to Processing so hopefully this makes sense: Am currently running voltage.ino on an Arduino and am graphing the voltage in Processing using read\_voltage.pde. This allows me to see a visual of the vol…

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## [Rotating Object with Leap Motion](https://discourse.processing.org/t/rotating-object-with-leap-motion/14560)

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**Author:** [@hamishryan6](https://discourse.processing.org/u/hamishryan6)\
**Replies:** 1\
**Last updated:** [October 10, 2019, 12:05am UTC](https://discourse.processing.org/t/rotating-object-with-leap-motion/14560 "2019-10-10T00:05:20Z")

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Hi All, I am having trouble using Processing with my Leap Motion device. I want to be able to rotate an image depending on where my pinky is on the screen. Therefore, I am trying to find the angle between my thumb (wher…

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## ["Reset" blur filter](https://discourse.processing.org/t/reset-blur-filter/14501)

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**Author:** [@kirillg](https://discourse.processing.org/u/kirillg)\
**Replies:** 2\
**Last updated:** [October 9, 2019, 9:34pm UTC](https://discourse.processing.org/t/reset-blur-filter/14501 "2019-10-09T21:34:33Z")

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My very first steps with Processing, and I couldn’t find the answer after Googling it for some time. size(640, 360); background(204, 153, 0); smooth(); background(0); noStroke(); fill(255,0,0); ellipse(100,100,12,12);…

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## [Mouse Press Redraw Loop](https://discourse.processing.org/t/mouse-press-redraw-loop/14555)

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**Author:** [@Killerherts](https://discourse.processing.org/u/Killerherts)\
**Replies:** 5\
**Last updated:** [October 9, 2019, 7:30pm UTC](https://discourse.processing.org/t/mouse-press-redraw-loop/14555 "2019-10-09T19:30:31Z")

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Thanks for taking the time to look at this, I am a beginner working on a racing game for a final project. My goal is to have the race start after a mouse or key press I was able to achieve this but my object jumps to th…

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## [Local variable x may not have been initialized](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477)

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**Author:** [@FilDomInteractive](https://discourse.processing.org/u/FilDomInteractive)\
**Replies:** 8\
**Last updated:** [October 9, 2019, 1:57pm UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477 "2019-10-09T13:57:22Z")

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I’m completely new to processing, i’m making a calculator. Please help me! boolean selected = false; float x; float y; { x = 0; y = 0; } void setup() { smooth(8); size(350,450); selected = true; } void draw(…

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## [Cannot center rectangle](https://discourse.processing.org/t/cannot-center-rectangle/14543)

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**Author:** [@organelle](https://discourse.processing.org/u/organelle)\
**Replies:** 3\
**Last updated:** [October 9, 2019, 10:37am UTC](https://discourse.processing.org/t/cannot-center-rectangle/14543 "2019-10-09T10:37:48Z")

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The rectMode(CENTER) cannot center my rectangle in my canvas. How do I fix this?

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## [Bezier. Solving X,Y](https://discourse.processing.org/t/bezier-solving-x-y/14492)

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**Author:** [@edward](https://discourse.processing.org/u/edward)\
**Replies:** 17\
**Last updated:** [October 9, 2019, 10:10am UTC](https://discourse.processing.org/t/bezier-solving-x-y/14492 "2019-10-09T10:10:37Z")

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Hello friends, I’ve been trying to find the Y coordinates of a Bezier Curve given X. I’ve been fairly successful getting approximate values by putting in an array lots of x values corresponding to “t” using the bezier…

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## [Arduino DCC interface with processing Software](https://discourse.processing.org/t/arduino-dcc-interface-with-processing-software/14541)

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**Author:** [@Paul63](https://discourse.processing.org/u/Paul63)\
**Replies:** 2\
**Last updated:** [October 9, 2019, 9:09am UTC](https://discourse.processing.org/t/arduino-dcc-interface-with-processing-software/14541 "2019-10-09T09:09:23Z")

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Hi all I am Paul from Italy, I am beginner with Processing , I sow one railway application on internet. I like know if somebody have experience to interface Arduino with Processing software to manage in DCC railway mo…

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## [Leap Motion - Detect the number of hands visible](https://discourse.processing.org/t/leap-motion-detect-the-number-of-hands-visible/14514)

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**Author:** [@hamishryan6](https://discourse.processing.org/u/hamishryan6)\
**Replies:** 1\
**Last updated:** [October 8, 2019, 12:03pm UTC](https://discourse.processing.org/t/leap-motion-detect-the-number-of-hands-visible/14514 "2019-10-08T12:03:37Z")

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Hi All, I have only just started using Leap Motion in Processing and I was wondering if there is a way of detecting how many active hands are being detected by the Leap Motion device. I want to make an ellipse appear wh…

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## [How to export frames from processing](https://discourse.processing.org/t/how-to-export-frames-from-processing/14494)

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**Author:** [@Malvan](https://discourse.processing.org/u/Malvan)\
**Replies:** 2\
**Last updated:** [October 8, 2019, 10:51am UTC](https://discourse.processing.org/t/how-to-export-frames-from-processing/14494 "2019-10-08T10:51:50Z")

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Hello there! I got a problem with the following code: PGraphics pg; float fontSize; int cols = 30; int rows = 30; float zoff = 0; float xoffsp = 0.2; float yoffsp = 0.2; float zoffsp = 0.05; float sizes; floa…

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## [PShader as background](https://discourse.processing.org/t/pshader-as-background/14495)

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**Author:** [@rojele](https://discourse.processing.org/u/rojele)\
**Replies:** 2\
**Last updated:** [October 8, 2019, 7:58am UTC](https://discourse.processing.org/t/pshader-as-background/14495 "2019-10-08T07:58:42Z")

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Hi, everyone, and thanks in advance for any help. In order to achieve this, I’m trying actually to apply the PShader to a PGraphics object, and then pass this PGraphics as an argument for the background. When I use the…

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