# Drawing background in setup function and changing renderer to P2D/P3D
**URL:** https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637
**Category:** Processing.py
**Created:** [January 15, 2022, 3:12pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637 "2022-01-15T15:12:49Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Setsuna](https://discourse.processing.org/u/Setsuna)
#### Post date: [January 15, 2022, 3:12pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637/1 "2022-01-15T15:12:49Z")
Hello everyone,
I use python mode and Processing 3.5.4.
I would like to use the setup function to draw background elements once before animating in the draw function. However, have an issue when I choose the P2D or P3D renderer.
```auto
def setup():
size(400,400)
ellipse(200,200,30,30)
def draw():
rect(100,100,20,20)
```
In this case, the circle is drawn once in the setup function, and then the rectangle in the draw loop. However, if I change rendering modes by using: size(400,400,P2D) or P3D, the circle is overdrawn and disappears.
How can I avoid that if I want to draw something just once, out of the drawing loop? Is drawing in setup a bad practice?
To circumvent that problem, I tried to use a method I found in a tutorial, using loadPixels but it doesn’t work either.
```auto
background_image = None
def setup():
size(400,400,P2D)
global background_image
background_image= createImage(400,400,RGB)
ellipse(200,200,30,30)
loadPixels()
background_image.loadPixels()
background_image.pixels = pixels
background_image.updatePixels()
def draw():
background(background_image)
rect(100,100,20,20)
```
What am I doing wrong?
Thanks!
---
### Author:  [@villares](https://discourse.processing.org/u/villares)
#### Post date: [January 15, 2022, 10:15pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637/2 "2022-01-15T22:15:19Z")
Cheers @Setsuna!
I think it could be some bug/issue involving the P2D/P3D renderer, I have seen them interact badly with some video card setups recently, but I don’t have much information to add unfortunately. ☹
It did not disapear for me:
See if this at the start of the sketch helps:
```python
from java.lang import System
System.setProperty("jogl.disable.openglcore", "false")
```
Your method of drawing to a PImage image buffer (`background_image`) should work without any `.pixel` load/updates, but when used as background inside `draw ()`it seems to me it would not result different to directly drawing the ellipse again and again in `draw()` 🤔
---
### Author:  [@tabreturn](https://discourse.processing.org/u/tabreturn)
#### Post date: [January 15, 2022, 10:31pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637/3 "2022-01-15T22:31:01Z")
Like @villares, I couldn’t replicate this issue either (on Linux).
Perhaps you could separate your code into `settings()` and `setup()` functions. I’ve no idea if this would help, but you could try –
```python
def settings():
size(400,400,P2D)
def setup():
ellipse(200,200,30,30)
def draw():
rect(100,100,20,20)
```
To be honest, I’m confused why you just don’t move the circle line to the `draw()` function. The visual result is identical –
```python
def setup():
size(400,400,P2D)
def draw():
ellipse(200,200,30,30)
rect(100,100,20,20)
```
But perhaps there’s some particular reason? if you can explain that use-case, maybe there’s another approach we can devise.
---
### Author:  [@Setsuna](https://discourse.processing.org/u/Setsuna)
#### Post date: [January 16, 2022, 12:03pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637/4 "2022-01-16T12:03:12Z")
Thank you @villares and @tabreturn for trying to replicate my issue. I use windows 10 and have an NVIDIA GeForce RTX 2060, it that’s worth anything. I still don’t get why the loadPixel solution doesn’t work.
I tried both of your solutions and it didn’t change the result. I see the setup frame with the circle for a split second and then it disappears.
My reason for trying this way is that in my actual program, my background image is made of many pixels, and the drawing loop animates many elements. The performance becomes bad if I draw the background in every loop. I also need to use P3D because I want to use ModelX and ModelY to get absolute coordinates. The actual project has become quite big so that’s why I posted just a simple example.
---
### Author:  [@villares](https://discourse.processing.org/u/villares)
#### Post date: [January 16, 2022, 1:40pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637/5 "2022-01-16T13:40:40Z")
I now understand why you need the fixed background! I’ll will try some other pre-draw alternatives. 😮
Another wild thing to try, one of my students, if I remember correctly, improved on his P3D problems by adding the seemingly useless `frameRate(60)` to the code. You might want to try that. 🙂
Another desperate thing would be to try another Processing+Python experimental tool: [py5.ixora.io](http://py5.ixora.io) and see if you get the same renderer issues 🤔
---
### Author:  [@villares](https://discourse.processing.org/u/villares)
#### Post date: [January 16, 2022, 2:34pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637/6 "2022-01-16T14:34:09Z")
Cheers @Setsuna !
See if this helps, back with the image buffer option, it worked for me:
```python
def setup():
global bg
size(400, 400, P3D)
bg = createGraphics(400, 400)
bg.beginDraw() # important!
bg.clear() # transparent background if you like
bg.ellipse(200, 200, 30, 30) # drawing on the buffer/offscreen surface
bg.endDraw() # also needed!
def draw():
background(bg)
rect(100, 100, 20, 20)
```
Another performance optimization for not redrawing too much stuff in draw could be using a PShape group. You can do polygons with `beginShape()` & `endShape()` and etc. Check the [createShape() reference](https://processing.org/reference/createShape_.html)!
```python
def setup():
global bg
size(400, 400, P3D)
bg = createShape(GROUP)
e = createShape(ELLIPSE, 200, 200, 30, 30)
bg.addChild(e)
def draw():
shape(bg, 0, 0)
rect(100, 100, 20, 20)
```
---
### Author:  [@Setsuna](https://discourse.processing.org/u/Setsuna)
#### Post date: [January 16, 2022, 4:09pm UTC](https://discourse.processing.org/t/drawing-background-in-setup-function-and-changing-renderer-to-p2d-p3d/34637/7 "2022-01-16T16:09:46Z")
Yay, both solutions work! I will use createGraphics for now and look into PShape if I need further optimization.
Thank you so much @villares , hope you have a great day!