Back to For Beginners

Gravity's affect on velocity implemented with speed and direction.

For Beginners

Started by Fl00Fy April 19, 2013 06:37 PM

3 comments, last by Fl00Fy 11 years ago

Fl00Fy

198

Author

April 19, 2013 06:37 PM

Sorry if the title's a bit confusing, had trouble trying to summarise the problem in a good way.

Anywho, it seems I may have coded myself into a bit of pickle. I'm trying to create a game which includes gravity and some stuff which is affected by it... I decided, when I started the project, that I would describe each objects velocity with two scalars: speed and direction (in radians, right being 0). It's worked out well so far, until I tried to implement gravity.

The problem is, I can't figure out how to account for gravity by giving the object a downward force. If this just happens to be a bad way to implement velocity, I would be alright with having to change the code to use a different method; but if there is a viable solution for this, I'd love to hear it.

Help of any kind would be appreciated.

Paradigm Shifter

5,832

April 19, 2013 07:21 PM

Use a 2d vector for your velocity instead. You can convert your direction and speed into a vector easily using trig.

"Most people think, great God will come from the sky, take away everything, and make everybody feel high" - Bob Marley

Nercury

820

April 19, 2013 07:25 PM

My article may help to get started with vectors.

BeerNutts

4,410

April 19, 2013 07:57 PM

You can always use "pseudo" gravity as well, just by adding to the Y-position by an increasing gravity value:


void PhysicalObject::Update(double deltaTime)
{
  if (NotOnGround) {
    YPosition += GravityVelocity;
    GravityVelocity += GravityAcceleration*deltaTime;
  }
  else {
    GravityVelocity = 0;
  }
}

My Gamedev Journal: 2D Game Making, the Easy Way

---(Old Blog, still has good info): 2dGameMaking
-----
"No one ever posts on that message board; it's too crowded." - Yoga Berra (sorta)

Fl00Fy

198

Author

April 19, 2013 08:03 PM

Thanks for all the advice. I'll probably end up adding the vector implementation. It's about time I start using them to be honest. And the article was a great help, thanks.

Gravity's affect on velocity implemented with speed and direction.

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Gravity's affect on velocity implemented with speed and direction.

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines