Gravity on an inclining plane

Math and Physics Programming

Started by Gammastrahler May 17, 2002 08:02 AM

6 comments, last by Gammastrahler 21 years, 11 months ago

150

Author

May 17, 2002 08:02 AM

hi, i have a question: if i jump my character up, the gravity pulls him down again, so far so good. but when i climb an inclining plane, say, 75 degrees, then it is normal that i can only move a little bit up until a force pulls me down (you see this in games like unreal). is this a gravity force or a friction force? and how can i calculate this force and how it is applied to my movement vector? thanks! Gammastrahler

deformed rabbit

124

May 17, 2002 08:29 AM

I''d say they''re modelling gravity (dragging the player down) and a _lack_ of friction on the inclining plane (the player can''t keep traction).

But its also game mechanics/design, to prevent the player getting to the border of the level, or a hidden area, or a poorly modelled area.

---------"It''s always useful when you face an enemy prepared to die for his country. That means both of you have exactly the same aim in mind." -Terry Pratchett

Zanthos

300

May 17, 2002 03:46 PM

I'm awful at physics, have a look.. no idea if its ok or not.. I'm sure someone will correct me if it isn't

As you can see the player isn't going up the slope any time soon with a forward motion of 400~N.

You could expand on it further with the formula F=ma.

[edited by - Zanthos on May 17, 2002 4:46:55 PM]

Gammastrahler

150

Author

May 17, 2002 04:25 PM

@Zanthos:

thanks, that helped me a lot!! now i have a good imagination and can start to code it.

i´m not an expert but i thought that the mass can be ommited, is this true?

thanks
Gammastrahler

Zanthos

300

May 17, 2002 05:13 PM

I wouldn''t think so, because:

Force = mass * acceleration, acceleration is gravity

Up is positive on my diagram, force due to gravity acts down perpendicular to the plane, so its negative:

Force = 70kg * -9.8 Sin75