Scratch
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#1 2007-03-12 19:59:26
- andymilburn
- Scratcher
- Registered: 2007-03-06
- Posts: 2
Collision detection with hidden objects
I THINK that hidden objects can sometimes return true for "touching"
in the java-compiled browser-based version of a scratch project.
This appears to be different than the behavior of the same project
running in the Scratch app locally.
If this seems absurd or confusing, I'll try to work up a bit of test code
to isolate the problem...
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#2 2007-03-13 10:00:10
Re: Collision detection with hidden objects
You are 100% right about this. See this project for proof.
http://scratchr.org/projects/debugjay/371
We'll work on debugging that.
From project notes on debug project:
this project has two invisible cats, one on the left and one on the right. one is hidden via "set ghost to 100" while the other is hidden via "hide" block. the visible cat changes color when he is "touching" the cat on the right and whirls when "touching" the cat on the left. despite their invisibility, the collisions are detected. this is different from the behavior in the scrtach programming environment where the collisions are not detcted.
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#3 2007-03-15 19:58:13
Re: Collision detection with hidden objects
This is fixed now. Note that even though you can't touch a sprite that is hidden, its scripts are still running and it can touch any non-hidden sprite. (So you can have a treasure sprite reveal itself when a character touches it.)
Last edited by johnm (2007-03-15 19:58:57)
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#4 2011-05-26 16:13:00
- Ashurathehedgehog
- Scratcher
- Registered: 2010-12-16
- Posts: 100+
Re: Collision detection with hidden objects
andymilburn wrote:
I THINK that hidden objects can sometimes return true for "touching"
in the java-compiled browser-based version of a scratch project.
This appears to be different than the behavior of the same project
running in the Scratch app locally.
If this seems absurd or confusing, I'll try to work up a bit of test code
to isolate the problem...
Try going on the flash player, also...FIRST COMMENT IN 3 YEARS ON THIS BOARD!
Oh great. hit my 100th post. thankz liru.
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#5 2011-05-26 17:15:45
- scratch_yoshi
- Scratcher
- Registered: 2009-06-12
- Posts: 1000+
Re: Collision detection with hidden objects
Ashurathehedgehog wrote:
andymilburn wrote:
I THINK that hidden objects can sometimes return true for "touching"
in the java-compiled browser-based version of a scratch project.
This appears to be different than the behavior of the same project
running in the Scratch app locally.
If this seems absurd or confusing, I'll try to work up a bit of test code
to isolate the problem...Try going on the flash player, also...FIRST COMMENT IN 3 YEARS ON THIS BOARD!
That's called a necropost. It makes you look stupid 
We don't usually like reviving old(in this case, 3-year-old) topics from the dead.
Retired from Scratch, but just the language itself. Not the forums.
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#6 2011-05-26 17:19:23
- CloneCommando1
- Scratcher
- Registered: 2010-12-02
- Posts: 500+
Re: Collision detection with hidden objects
I agree with scratch_yoshi. Except for the "makes you look stupid" part.
RANDOM THOUGHT: If the tomato is a fruit, doesn't that make ketchup a smoothie?
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#7 2011-05-26 20:42:20
Re: Collision detection with hidden objects
scratch_yoshi wrote:
Ashurathehedgehog wrote:
andymilburn wrote:
I THINK that hidden objects can sometimes return true for "touching"
in the java-compiled browser-based version of a scratch project.
This appears to be different than the behavior of the same project
running in the Scratch app locally.
If this seems absurd or confusing, I'll try to work up a bit of test code
to isolate the problem...Try going on the flash player, also...FIRST COMMENT IN 3 YEARS ON THIS BOARD!
That's called a necropost. It makes you look stupid
We don't usually like reviving old(in this case, 3-year-old) topics from the dead.
Yeah, necroposting isn't exactly something to be proud of.
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