# question 4 the professionals : variable gravity , bAAh !

hi , how can someone make a graviety that changes with the tepography of
the track , just consider that there is a spiral street like in the
game sonic

how can i make the graviety catch him to the floor like in this image

look at this image

help me if you can , thanks

is the question hard ?? i have no idea to do that

That’s centrifical force that does that. The faster the driver is going the more the bike lays down in a turn. It will probably look pretty good if the bike just lays down when turning, so an action or ipo connected to the turning keys would look pretty good. If you took velocity into account it would look a little better.

Maybe add velocity in the oposite direction of the normal of the object u are above of with gravity set to 0

can you make an example of blend file

a spiral level and any object as driver

thanks for trying to help

4reviving…

Sensor---->Controller---->Actuator

Collision plane–>And-----> Prop centrifuge TRUE

Centrifuge TRUE–>And—> -z Force (local)

Collision plane2–>And—> Centrifuge FALSE

Not the best diagram, but do you think that’ll work?

Collision(prop:upsidedown) -> AND -> Motion(force(-15Z)L)

Collision(prop:upsidedown) -> AND -> Motion(force(-15Z)L)

what the ??? is that a python code … i know nothing i python

Sensor---->Controller---->Actuator

Collision plane–>And-----> Prop centrifuge TRUE

Centrifuge TRUE–>And—> -z Force (local)

Collision plane2–>And—> Centrifuge FALSE

Not the best diagram, but do you think that’ll work?

that isn’t too clear , thanks anyway …

Those are logic bricks - what we are saying is that you need to have a plane with ‘ghost’ enabled. Set up the bike so that when it is touching the plane, a property is on, and when it is not touching, the property is off. Then set it up so when the property is on, do a motion actuator of -Z local to disable gravity, or even push the bike down(locally) against the track.

To correctly do this it would require complex python - on the area of the loop, you would put an invisible ghost grid, and when the player is touching the grid, you would make a mathematical function that assigns gravity according to the rotation and Z position of the bike.

Here’s what I was talking about:
How to do an inversion
The light pink cube is the racer. The dark pink loop is a ghost object with property “upsidedown”. The black loop is the racetrack. The logicbricks belong to the racer.