Stop sprites bouncing when using gravity.

Hotwire

Something I've never figured out is how to add gravity so that sprites don't fall into blocks but also don't bounce.
http://scratch.mit.edu/projects/14757194/

Here's what I mean.
Currently if it's touching the ground the character will move up, if not the character to will move down.
The y velocity is set to 5 if touching the ground to stop the character falling in.

I can do double layers on the ground and reduce it, but I can't do it with just one layer.

lederniersamourai

You might add acceleration, i.e. “velocity” of velocity.
When touching the ground acceleration makes velocity decrease.
When moving this will make velocity increase.
Note the if your accelration take only v3 values for instance (0, 1, 5 and same negative values), you can encode that in the formulas that change the velocity.

Hotwire

lederniersamourai wrote:
You might add acceleration, i.e. “velocity” of velocity.
When touching the ground acceleration makes velocity decrease.
When moving this will make velocity increase.
Note the if your accelration take only v3 values for instance (0, 1, 5 and same negative values), you can encode that in the formulas that change the velocity.

Did you look at the project I posted?

drmcw

Hotwire

drmcw wrote:

No, that will not allow the sprite to rise when below the background.
If travelling along the line it won't follow it.

drmcw

That's why it's bouncing. Either set it to a small value or change the way you do things and have a repeat until not touching, move -1 function to move out the ground.

Hotwire

drmcw wrote:
That's why it's bouncing. Either set it to a small value or change the way you do things and have a repeat until not touching, move -1 function to move out the ground.

*sigh* thanks for not helping…

drmcw

You're more than welcome.

AonymousGuy

I would use a sensor sprite (could even be a clone of the main sprite) which checked to see if it was on the ground.

Hotwire

AonymousGuy wrote:
I would use a sensor sprite (could even be a clone of the main sprite) which checked to see if it was on the ground.

Oh, right… explain more?

AonymousGuy

Hotwire wrote:
AonymousGuy wrote:
I would use a sensor sprite (could even be a clone of the main sprite) which checked to see if it was on the ground.
Oh, right… explain more?

I made an example project which shows this method using a sprite which creates a clone of itself. Sorry if the project is hard to understand!

scubajerry

http://scratch.mit.edu/projects/13421701/

Hotwire

Ah, dw I've got something now.

Last edited by Hotwire (Nov. 29, 2013 19:04:02)

xlk

Hotwire wrote:

Ah, dw I've got something now.

put this in a custom block set to run without screen refresh:
repeat until <not<touching BG>>
change y by

drmcw

Going back to the beginning…what's wrong with setting yv to 1 or is that still too bouncy?

Hotwire

drmcw wrote:
Going back to the beginning…what's wrong with setting yv to 1 or is that still too bouncy?

Yes, it also means that the sprite will fall into the blocks before coming back out to make small bounces on the surface.

lederniersamourai

So, what you meant is thant when touching ground, you want to move to the exact (perpendicular) distance between ground and the bottom of your sprite.
You can do that by making a block computing that with a binary search with an auxiliary sprite that is shown but made totally ghost.
This is what drmcw proposed except that had to be done on an auxiliary sprite …

Hotwire

lederniersamourai wrote:
So, what you meant is thant when touching ground, you want to move to the exact (perpendicular) distance between ground and the bottom of your sprite.
You can do that by making a block computing that with a binary search with an auxiliary sprite that is shown but made totally ghost.
This is what drmcw proposed except that had to be done on an auxiliary sprite …

Problem is resolved no worries.

1timetraveler

i am working on a project (Test) that envolves just this so ill give you the link when its finished or just look on my page

1timetraveler

http://scratch.mit.edu/projects/24452320/#player

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