Hello Guys ,

I am developing a running game in which player jump overs the obstacles . I am confused how to make conditions for jumping . So , that if player did anything wrong , player collides with the obstacles . in starting , first i get the horizontal distance which is to be covered and using this and current speed calculate the time required and using this time calculates the jump required . But , in this situation. Player covers all the obstacles without any difficulty . So , i change my approach and instead of time i use height required to jump over obstacle . In the later approach there is no speed involve and player is doing mistakes if player jump after certain point .

But , i want to know how mechanics work in these running and jumping game ? Some tutorial or advice . I will be very thankful to you .

I would have solved this problem with simple classic physics. Look at your problem as a composite system. Your character got a force which makes it move. Futhermore the character would have a force, which makes it jump. It may also have a drag force, and lastly a gravity force.

By using D'Alembert's principle, you would calculate the final force, which is acting on the object. It implies that, if we have a set of forces acting on an object, we can replace all those forces with a single force, which is done by just summing the forces together.

So I would have calculated the forces, the acceleration, the velocity and the position of you character, by using vector math. Then i would just do a simple bounding box test between the character and the obstacle, to check if the character is inside.

Here is a link for a simple tutorial, which explains what i have mentioned.
http://ianqvist.blogspot.no/2009/09/2d-physics-engine-tutorial-part-3.html

In addition to what was said above, you could look into thinking about a double-tap jump being higher than a single tap for example. It will help to simplify the mechanic.

Thanks guys . Your collective info. solves my problem .