Scratch

THEphish · 2012-06-24 08:43:59

Hi, I'm creating a simple maze game at the mo called Planez in which I have sprites bouncing off walls. However, when a sprite goes diagonally at a wall it goes straight through. I wrote an explanation about it in a post called 2 Player Maze Game - Help!!! but as it is in a post originally about something else, I thought maybe making a new post about it would help people find it. If you can't find my post here's a link:
http://scratch.mit.edu/forums/viewtopic.php?pid=1289707#p1289707

Please help me find a solution!

wahoo77 · 2012-06-25 16:00:10

Use this block


if on edge, bounce

northmeister · 2012-06-25 16:20:57

wahoo77 wrote:
Use this block
if on edge, bounce

That's to bounce back off the edge of the screen, I think he means bounce it off the maze walls.

pipercubjl · 2012-06-26 16:45:16

when  clicked
forever
if up key pressed
change y by 1
if touching maze ▼
change y by -1
if down key pressed
change y by -1
if touching maze ▼
change y by 1
if right key pressed
change x by 1
if touching maze ▼
change x by -1
if left key pressed
change x by -1
if touching maze ▼
change x by 1

Last edited by pipercubjl (2012-06-26 16:47:50)

fg123 · 2012-06-26 17:40:39

Here is what you need:
http://scratch.mit.edu/projects/fg123_tests/2637559

MoreGamesNow · 2012-06-26 21:13:27

pipercubjl wrote:

when  clicked
forever
if key up arrow ▼
 pressed?
change y by 1
if touching maze ▼
?
change y by -1
if key down arrow ▼
 pressed?
change y by -1
if touching maze ▼
?
change y by 1
if key right arrow ▼
 pressed?
change x by 1
if touching maze ▼
?
change x by -1
if key left arrow ▼
 pressed?
change x by -1
if touching maze ▼
?
change x by 1

Fixed blocks.

If you want velocity:

when  clicked
set x-vel ▼
 to 0
set y-vel ▼
 to 0
set accel ▼
 to whatever number you want
forever
ifkey up arrow ▼
 pressed?
change y-vel ▼
 by accel
ifkey down arrow ▼
 pressed?
change y-vel ▼
 by -1
*accel
ifkey right arrow ▼
 pressed?
change x-vel ▼
 by accel
ifkey left arrow ▼
 pressed?
change x-vel ▼
 by -1
*accel
set x-vel ▼
 to 0.98
*x-vel
set y-vel ▼
 to 0.98
*y-vel
change x by x-vel
iftouching wall ▼
?
change x by -1
*x-vel
set x-vel ▼
 to -0.5
*x-vel
change y by y-vel
iftouching wall ▼
?
change y by -1
*y-vel
set y-vel ▼
 to -0.5
*y-vel

fg123 · 2012-06-27 01:21:09

Overly complicated. tongue He wants the code for bouncing off walls diagonally, not velocity and movement. tongue

fg123 wrote:
Here is what you need:
http://scratch.mit.edu/projects/fg123_tests/2637559

MoreGamesNow · 2012-06-27 09:09:45

fg123 wrote:
Overly complicated. He wants the code for bouncing off walls diagonally, not velocity and movement.

Like pong? Because the easiest way to have accurate collision like that is the script below. 90 degree walls are nice because the absolute value of the x and y velocities are always constant.

A lot of users simply turn the sprite 180 degrees though, which isn't accurate collision. It's easier to simply avoid angles all together and use x and y velocities.

when  clicked
forever
change x by x-speed
iftouching wall ▼
?
set x-speed ▼
 to -1
*x-speed
change x by x-speed
change y by y-speed
iftouching wall ▼
?
set y-speed ▼
 to -1
*y-speed
change y by y-speed

Last edited by MoreGamesNow (2012-06-27 09:26:29)

THEphish · 2012-06-30 11:35:52

Thanks MoreGamesNow I used that and it works really well! I've credited you in the project notes. My game is now online at:
http://scratch.mit.edu/projects/THEphish/2645424
It isn't perfect yet, and graphically looks bad, but I'm gonna improve it later. Sorry fg123, that wasn't for me.

Scratch

archived forums

#1 2012-06-24 08:43:59

Problems with sprites bouncing off walls

#2 2012-06-25 16:00:10

Re: Problems with sprites bouncing off walls

#3 2012-06-25 16:20:57

Re: Problems with sprites bouncing off walls

wahoo77 wrote:

#4 2012-06-26 16:45:16

Re: Problems with sprites bouncing off walls

#5 2012-06-26 17:40:39

Re: Problems with sprites bouncing off walls

#6 2012-06-26 21:13:27

Re: Problems with sprites bouncing off walls

pipercubjl wrote:

#7 2012-06-27 01:21:09

Re: Problems with sprites bouncing off walls

fg123 wrote:

#8 2012-06-27 09:09:45

Re: Problems with sprites bouncing off walls

fg123 wrote:

#9 2012-06-30 11:35:52

Re: Problems with sprites bouncing off walls

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