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#1 2012-02-12 14:17:05

natashasharan
New Scratcher
Registered: 2012-02-11
Posts: 1

How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

So I use the Drawing_Pencil  sprite to draw a line.  Now I want my car sprite to follow along that line .  How can I do it ?

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#2 2012-02-12 14:18:04

gabric
Scratcher
Registered: 2011-07-23
Posts: 100+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

Is the line straight?


http://mag.racked.eu/cimage/i57.1/Found+a+good+server%21/Welcome+to+CupCake+Craft%21/mca.png

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#3 2012-02-12 15:16:44

HD123
Scratcher
Registered: 2009-12-05
Posts: 500+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

First, have the car go to the start of the line.  Draw a red and a blue sensor on the left and right sides of the car.  Point the car in the starting direction, and then you can use this script:

when i receive
drive
forever
move
1
steps
if
color
is touching
repeat until
not
color
is touching
turn
-1
degrees
if
color
is touching
repeat until
not
color
is touching
turn
1
degrees

If that doesn't work, try reversing the red and blue colors.

Last edited by HD123 (2012-02-12 15:18:02)


~~HD123~~
Treat others as you want to be treated. |  big_smile  | http://i.imgur.com/OaNrY.gif | http://blocks.scratchr.org/libstatus.php?user=HD123&online=http://lemonfanatic.webs.com/ONLINE.png&offline=http://lemonfanatic.webs.com/OFFLINE.png

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#4 2012-02-12 18:14:15

gabric
Scratcher
Registered: 2011-07-23
Posts: 100+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

HD123 wrote:

First, have the car go to the start of the line.  Draw a red and a blue sensor on the left and right sides of the car.  Point the car in the starting direction, and then you can use this script:

when i receive
drive
forever
move
1
steps
if
color
is touching
repeat until
not
color
is touching
turn
-1
degrees
if
color
is touching
repeat until
not
color
is touching
turn
1
degrees

If that doesn't work, try reversing the red and blue colors.

If the line is straight then there is an easier way.


http://mag.racked.eu/cimage/i57.1/Found+a+good+server%21/Welcome+to+CupCake+Craft%21/mca.png

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#5 2012-02-12 18:28:52

bobbybee
Scratcher
Registered: 2009-10-18
Posts: 1000+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

Heres another way. Assume that x1, x2, y1, and y2, are the coordinates of the points in the line.

when clicked
set
angle
to
atan
of
x2
-
x1
/
y2
-
y1
forever
change x by
cos
of
angle
change y by
sin
of
angle

Last edited by bobbybee (2012-02-14 19:27:17)


I support the Free Software Foundation. Protect our digital rights!

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#6 2012-02-12 21:02:05

landonpants13
New Scratcher
Registered: 2012-02-12
Posts: 2

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

I tried your idea, but it didn't work.  Here is my scratch file:

http://dl.dropbox.com/u/61958901/Robot%20Racecar.sb

Thanks in advance!!
Landon

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#7 2012-02-12 23:11:09

CheeseMunchy
Scratcher
Registered: 2008-10-13
Posts: 1000+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

there's this:

when clicked
forever
glide 0.5 seconds
or whatever
to sprite1
or this
when clicked
forever
go to x:
x position
of
sprite1
+ 20
y:
y position
of
sprite1

Or some other things that will probably be harder.

Last edited by CheeseMunchy (2012-02-12 23:12:59)


6418,

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#8 2012-02-12 23:24:37

Luxturna
Scratcher
Registered: 2011-04-24
Posts: 38

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

natashasharan wrote:

So I use the Drawing_Pencil  sprite to draw a line.  Now I want my car sprite to follow along that line .  How can I do it ?

not sure HOW to do it, but can you add a link to the project?


http://scratch.mit.edu/static/icons/buddy/782569_med.png?t=2012-03-10+00%3A38%3A57

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#9 2012-02-14 19:15:11

360-International
Scratcher
Registered: 2011-07-17
Posts: 100+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

bobbybee wrote:

Here's another way. Assume that x1, x2, y1, and y2, are the coordinates of the points in the line.

when clicked
set
angle
to
atan
of
x2
-
x1
/
y2
-
y1
forever
change x by
cos
of
angle
change y by
sin
of
angle

Fixed.


https://lh4.googleusercontent.com/Oib6kyze-OrCFIRlqL6HYnWuHBQp1GfFoh5CkBlZGe3_9WCk-_DDwgfFrnD_mxJ_x2b18hMUyV2KVtIDiLdebyWaQQ6fbpKpZs-8auVep1zoSgOv-iA

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#10 2012-02-14 19:26:44

bobbybee
Scratcher
Registered: 2009-10-18
Posts: 1000+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

Thanks for the block fixing. (I don't understand how the forum blocks work...)


I support the Free Software Foundation. Protect our digital rights!

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#11 2012-02-18 11:27:19

landonpants13
New Scratcher
Registered: 2012-02-12
Posts: 2

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

how do i get to make your x and y thing?

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#12 2012-02-20 12:10:10

PencilFactory
Scratcher
Registered: 2011-11-11
Posts: 100+

Re: How To Follow along on a Line Drawn by Drawing_Pencil Sprite ?

as the drawing pencil is drawing add its position in a list
when the pencil is done drawing set pencil done drawing to 1

when clicked
set
pencil done drawing
to
0
forever
add
x position
to
pencil x
add
y position
to
pencil y
if
pencil done drawing
=
1
stop script

the car will go to those positions

when clicked
wait
1
secs
set
i
to
0
forever if
pencil done drawing
=
1
repeat
length of
pencil x
change
i
by
1
go to x:
item
i
of
pencil x
y:
item
i
of
pencil y

Last edited by PencilFactory (2012-02-20 12:20:16)


PencilFactory is http://blocks.scratchr.org/API.php?user=PencilFactory&action=onlineStatus&type=text, see my computerhttp://mag.racked.eu/cimage/i9002/Achievement+get%21/Computer+crashed/mca.png

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