Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels...

Scratch Primary Lesson 5

The XY Coordinate System

creativecomputerlab.com

The Scratch Stage• The scratch stage is 480 pixels wide and 360

pixels high:

The Pixel• The pixel is the smallest single component of a digital

image or a computer screen.• Pixels form a grid across the screen. Each pixel can be

given a color which makes up its part of an image.• In Scratch, one unit of x or y, or one step is equal to one

pixel:

Zoom in on the cat to see theindividual pixels in the image

X: -100

X Number Line• These are the x values for the scratch stage

– Where is 0? --Why are some x values negative?– What is half of 480?

Values for X:X: 100

Try This Experiment:• Build the script shown below:• Check the box to display the x position:

• Run the script and watch the sprite’s x values change:

• What is the x position when the script ends?creativecomputerlab.com

X Number Line• The left half of the stage has negative (-X) values.• The right half of the stage has positive (X) values

Negative X-X

X < 0-100 100

Positive XX

Move With The Arrow Keys• A negative number moves in the opposite

direction as a positive number.

• Positive numbers move x to the right ->

• Negative numbers move x to the left <-

Y Number Line• These are the y values for the scratch stage

– Where is 0? --Why are some y values negative?– What is half of 360?

Y: -100

Y: 100

Negative Y-Y

Positive YY

360Values for Y:

X and Y Values Combined

x, y-x, y

-x, -y x, -y

There are 4 ‘quadrants’. Each quadrant has a different combination of positive or negative x and y values:

The XY Coordinate System• Start a new project.• Select the “x-y grid

backdrop for the stage:

Moving In the XY Coordinate System

• Hook the right arrow key up to “change x by 10”:

• How are we going to move left?

• What about moving up and down?

• Can you make the sprite move with all 4 of the arrow keys by changing x and y?

Fun With The• Starts drawing

• Stops drawing

• Erases all drawings

• Sets the pen thickness

• Sets the pen’s colorcreativecomputerlab.com

Make A Drawing Program

– Hook all four arrow keys to change x and y by 10

– Now double click on the ‘pen down’ block:

– Set the pen thickness:

– Set the pen color:

Now move around with the arrow keys and draw!If you screen gets too messy you can click on

Make Rainbow Tracks• Program the scripts to

change the pen color each time the sprite moves. See what happens.

Going Places• Lets make the cat go to different XY locations on

the stage.• Make the cat go to the center of the stage:

• Make the cat go to the lower left of the stage:

• Make the cat glide to the upper right of the stage:

• See what happens when you make the glide for more than one second.

Explore the X and Y Space• Go to the “xyPosition” project at :

http://scratch.mit.edu/projects/12776565/• You can search for it by typing in “creativecomputerlab”,

then click on the “xyPosition” project:

• Play with the project and see the values for x and y change.creativecomputerlab.com

The Ant Farm GameThis is a programming challenge. Program the ant to reach the food without touching the sides in 2 ways:

1. Move the ant by using the arrow keys.

2. You are NOT allowed touse the arrow keys. You have to write a script so that the ant will move by itself whenyou push the 'Go!' button.

Make Your Own Copy Of The Ant Farm Game

http://scratch.mit.edu/projects/12778304/•Make your own copy of the game by:

1. Clicking on 2. When you are in the project click on 3. Change the name of the project from

to include your name:

• Go to the “Ant Farm” project at

Inside The Ant Farm Game

• The Ant: Make the ant move by adding scripts to move with the arrow keys:

Be careful that the ant doesn’t touch thesides of the tunnel! See what the script doesand play with it.

Challenge 1: Use arrow keys to move

Inside The Ant Farm Game

• The Ant: Make a script which makes the ant• move through the tunnel by itself without

using the arrow keys.

Hint: You can use these blocks:

You win when the ant touches the food at the upper right.

Challenge 2: Move the ant using a script.

Scratch Lesson 1 - CoderDojo Nelson€¦ · The Scratch Stage • The scratch stage is 480 pixels...

Documents

€¦ · Optical flow •How to estimate pixel motion from image I 1 to image I 2 ? •Solve pixel correspondence problem •given a pixel in I 1 , find pixels with similar color

Pixel art Bea - L ecole de crevette · Pixel art n° 37 . 36 x 32 = 1152 pixels Pixel art n° 39 . Title: Pixel art Bea.pub Created Date: 20150521190001Z

Dots / Pixels The most basic unit is the dot. A pixel is a picture element. A pixel is the smallest piece of information in an image. Dots, or pixels

Pro Display™ / Panasonic Pixel:13mm Pitch:15mm Module dimension:480 x 480mm Pixels per module:32 x 32 Pixels per m2: 4,444 Configuration: 1R1G1B Colour

Zero Distortion Mega Pixel Macro Lens 2Mega Pixel Objektiv Makro 2,0x verzeichnungsfrei Méga Pixels Macro-objectif 2,0x sans déformation 100-MC200 Specification 04/2014 - Specifications

CVF Open Access - PiCANet: Learning Pixel-wise …openaccess.thecvf.com/content_cvpr_2018/Supplemental/...pixel and the bottom two rows show two foreground pixels). The attended context

Pixels - sm1702vdi.files.wordpress.com · Pixels. Pixel A Pixel is the most smallest element of a digital image. It stores a single color or an intensity (for B&W images) Pixel In

IMAGE EDITING - · PDF file10.05.2017 · PIXELS •The computer stores and displays pixels, or picture elements. •A pixel is the smallest addressable part of the computer screen

Maquette de document NORME AERMC · Web viewhaut de 7 pixels, sauf pour la case de l'onglet "Rechercher" placé à 1 pixel. gauche de 5 pixels, une marge gauche de 0 pixel. Le champ

Module 4-5 Facebook Retargeting Pixels September 14, 2015halepringle.com/.../resources/Module-4-5-Facebook-Retargeting-Pixel… · Module 4-5 Facebook Retargeting Pixels September

RESOLUÇÃO DA IMAGEM O espaçamento dos pixels em uma imagem determina a sua resolução, medida em pixels por polegada (pixel per inch - ppi) ou ponto por

How to create a basic game in Scratch. The Scratch Stage The Scratch stage is 480 pixels wide and 360 pixels high. -240 240 180 -180 x increasesx decreases

SanDevices E681 Pixel Driver Documentation Sep 24 2011clearwaterlights.org/files/E681_opman.pdf · Including 5-bit, 8-bit, and 12-bit pixels. Multiple pixel types/voltages can be

Programming For Artists Lesson 8 Playing with pixels Learning objectives: Access and manipulate the pixel array

Product Specification M195RTN01 - sinsungdid.com General Description ... Pixels H x V - 1600(x3) x 900 Pixel Pitch [um] 0.2712 x 0.2626 Pixel Arrangement ... Product Specification

Sub-Pixel Layout for Super-Resolution with Images in the ...people.csail.mit.edu › hangzhao › posters › ECCV14_Poster.pdf · sub-pixels (treat as a dumb pixel). It also contributes

42 Version 5.11 USER MANUAL · Original Pixel 4 x 4 sub pixel matrix . Depending on the original pixel dimensions and the number of sub pixels used, the accuracy of our measurements

The ATLAS Pixel Detectorgilg/PixelOverviewPaper/PixelPaper-All/pixels...The ATLAS Pixel Detector ... for the pixel detector. This is followed by an overview of the system and its

Pixel Tutorial - Dibujo Pixels

Center Pixel Value Mean Value of All Pixels Percent of Pixels that meet QC Criteria Web and Web Services based tool that provides subsets and visualization