Update 17: Alpha 1.45 - Explosive Walls

I've been working on destructive terrain, and I decided the best way to blow up something, is to build it up first, literally brick by brick. As my current walls were just a (1,0.5,0.1) sized wall, I figured I should build it with 50 individual bricks into a prefab. Then when I apply force to it, it will spray across the screen in 50 pieces not one!

My first hurtle was that when I applied the rigid body property to all of the bricks, the wall tended to wobble like jelly (Jello for you Americans). I was able to solve this by not applying my RigidBody component (to enable physics) until the explosive force was applied. It actually turned out to be easier to apply this component to items in the blast radius rather than every single item on the screen. It's probably cheaper, (resource wise), too!

Next it was time to stack a few of these prefabs on top of each other, and then apply an explosive force to a random point in front of the wall... the resultant explosion was... unexpected. I'm still not sure why the explosion is along the z plane...

Moving on, applying the new prefab to my test level, it gives a far more satisfying burst across the screen when I throw grenades.

There is no download for this, I'm still adding some the next feature... which is visible in that last screenshot...

Update 16: Alpha 1.4: Throwing

In the last few Alpha releases, I've been focusing on stabilizing the camera and shooting mechanics. I feel much better about how it all looks, especially the camera movement, with all bugs around the camera now addressed.

Although I have a few timing issues with the shooting still to solve, I've moved on to the next type of attack, throwing grenades. I started by working through the physics and showing the trajectory. 

With the help of two very important links:

1. Some excellent theory from the Castle Story: http://www.sauropodstudio.com/dev-diary-number-eight/
2. A script to draw the line from Unity3D wiki: http://wiki.unity3d.com/index.php/Trajectory_Simulation

Using this, I was able to calculate the distance to the target, based on a fixed angle of 45 degrees: this meant that I can throw my grenade in a nice parabolic curve towards the target. 

Here are two screen shots showing this in action in my test level, with the red line replaced by a trail of smoke: 

Just before the grenade hits...

Just after the grenade hits...

When my grenade collides against my target, it 'explodes'. At the moment it's just an expanding red sphere - particle effects to come later. I use the Physics.OverlapSphere() function to look for items within a certain radius:

Collider[] hits = Physics.OverlapSphere(myProjectile.transform.position, explosionRadius);


If any of my collider hits are a player, I deal damage, but if it's destructible terrain, I use the AddExplosionForce() function like this:

//If destructible terrain was hit, destroy it
if (hit.collider.tag == "DestructibleTerrain") 
{
    //Add Rigidbody to terrain/wall
    hit.transform.gameObject.AddComponent<Rigidbody>();
    
    //Add explosive force at the point of the projectile impact
    hit.transform.rigidbody.AddExplosionForce(explosionForce, myProjectile.transform.position, explosionRadius);
}

This has two effects: it removes the destructible terrain from the explosion area, and it propels the same terrain across the map, which I think is pretty cool...

You can download version Alpha 1.4 here: http://www.samsmithnz.com/content/tbe/tbe_alpha1.4.zip.