BGP 2015 – sixth week: Development issues

Hello!

This week I started by giving the camera some simple movement behavior. Basically I make it follow the player’s position (with a certain offset) and rotation though somewhat slowly so that it’s movement becomes more smooth rather than sudden and jerky. I am mainly making use of ‘Slerp’ and ‘SmoothDamp’ for the camera’s movement.

I’ve also managed to get the direction correction for the movement to work as intended. What I had missed was that I needed to make use of conversion between local space and world space in the engine.

Here is a copy of the sample code if it’s hard to see:

1. // C# / UnityScript
2. var yVel = rigidbody.velocity.y;
3. var localV = transform.InverseTransformDirection( rigidbody.velocity );
4. localV.x = 0.0f;
5. localV.y = 0.0f;
6. var worldV = transform.TransformDirection( localV );
7. worldV.y = yVel;
8. rigidbody.velocity = worldV;

Taken from:

http://answers.unity3d.com/questions/412078/keeping-forward-velocity-always-in-the-same-direct.html

Lastly I encountered a problem with the rotation boxes (triggers that will rotate the player automatically, but only in the x-axis and z-axis) when they are used in the actual level we were going to use for the Beta.

For some reason they stop working properly when their local z-axis is aligned with the world y-axis. I thought I could fix this by making use of local rotation values just like I did with the movement but it ended up making things worse as all rotation boxes  regardless of placement stopped working properly.

Worst case scenario we will have to move on without any automatic rotation as there isn’t much time left.

Cheers!

BGP 2015 – fifth week: Trouble with player movement.

Hello!

This week I’ve mainly been working on the player movement. I tried making it more controllable by the player. This was done by changing the direction of the rigidbody’s velocity to a forward vector multiplied by the magnitude of the old velocity. However this meant that the parts of the velocity that made up movement other than acceleration, such as jumping or strafing, also became a forward vector. As such jumping, strafing, tackling and gravity was ruined, but the player did get better steering control over their vehicle. By drawing mind maps of the movement function and analyzing it, I tried to get the redirection of gravity apply to acceleration only while the other velocities, such as jumping and  strafing, were unaffected.

In the end, however, it turned out that using the old movement (without the redirected acceleration) with a largely increased drag on the rigidbody, from 0.5 to 2, worked better as it also gave the players control without affecting the gravity, jumping etc…

The big question now is which form of translation the movement should be made up of, by adding forces or affecting the rigidbody’s velocity directly? Add force might be the better alternative as using that means I will interfere less with Unity3D’s own physics engine, but I need a proper level to test the movement on now.

Cheers!

BGP 2015 – fourth week: loops, turns, rotations & illness

Hello!

This week has been pretty bad for me because I’ve been ill for the most part and as such have not been able to work as much on the project. It really does wonders for your stress levels.

I have been able fix the custom gravity effect for loops and turns by making prefabs that are essentially trigger boxes that apply a gravity effect on any players within them. The direction of the gravity effect is determined by the rotation of the object itself (which is invisible), or rather the direction of its local y-axis is the inverse of the gravity direction. This way anyone, not just programmers, can place and manipulate the custom gravity by rotation the objects and transform their trigger colliders. Indeed, they could even replace the box trigger colliders with trigger colliders of different shapes if they so desire, what’s important is the game objects rotation and that it has the gravity script attached to it. The script also has a public variable for multiplying the gravity strength if the need should arise.

This way it is possible to place several gravity objects with different rotations along the turn or loop in order to make it’s custom gravity.

I’ve made a similar type of game object that takes care of rotating the player as the level twists and turns as the players are not to be able to pitch or roll when on the track. They work in principle the same way as the gravity objects except they affect the players rotation instead. The rotation is handled by an individual type of object since the rotation and gravity direction don’t always coincide, they need to be independent of each other. Compare the image below that shows the rotation boxes for the loop with the image above that shows the gravity boxes for the same loop.

I’ve also managed to clean up some of the code. Previously the input form players and the player movement was in the same script so I had to make one for each player. Now those are separated, which should help make things easier from now on, at least when developing the player prefabs.

Cheers!