private void SetMomentOfInertia(InertiaBody body)
{
if (InertiaBody.NONE == body)
{
inertia = 0;
inertiaInv = 0;
return;
}
Vector3 hitboxSize = Vector3.zero;
MeshFilter meshFilter = gameObject.GetComponent <MeshFilter>();
SpriteRenderer renderer = GetComponent <SpriteRenderer>();
if (meshFilter != null)
{
hitboxSize.x = meshFilter.mesh.bounds.size.x * transform.localScale.x;
hitboxSize.y = meshFilter.mesh.bounds.size.y * transform.localScale.y;
}
else if (renderer != null)
{
hitboxSize.x = renderer.sprite.bounds.size.x * transform.localScale.x;
hitboxSize.y = renderer.sprite.bounds.size.y * transform.localScale.y;
}
//hitboxSize.z = mesh.bounds.size.z * transform.localScale.z;
switch (body)
{
case InertiaBody.RECTANGLE:
{
float dx = hitboxSize.x, dy = hitboxSize.y;
inertia = 1f / 12f * mass * (dx * dx + dy * dy);
break;
}
case InertiaBody.CIRCLE:
{
float radius = hitboxSize.x;
inertia = .5f * mass * radius * radius;
break;
}
case InertiaBody.ROD:
{
float length = hitboxSize.x;
inertia = 1 / 12f * mass * length * length;
break;
}
case InertiaBody.CIRCULAR_RING:
{
float outerRadius = hitboxSize.x;
float innerRadius = outerRadius * .75f;
float t = outerRadius - innerRadius;
float r = t / 2;
inertia = Mathf.PI * r * r * r * t;
break;
}
case InertiaBody.SQUARE:
{
float dim = hitboxSize.x;
inertia = (1f / 3f) * mass * dim * dim;
break;
}
}
inertiaInv = 1 / inertia;
}
private void SetMomentOfInertia(InertiaBody body)
{
inertia = Matrix4x4.identity;
inertiaInv = Matrix4x4.identity;
if (InertiaBody.NONE == body)
{
return;
}
Vector3 hitboxSize = Vector3.zero;
MeshFilter meshFilter = gameObject.GetComponent <MeshFilter>();
SpriteRenderer renderer = GetComponent <SpriteRenderer>();
if (meshFilter != null)
{
hitboxSize.x = meshFilter.mesh.bounds.size.x * transform.localScale.x;
hitboxSize.y = meshFilter.mesh.bounds.size.y * transform.localScale.y;
hitboxSize.z = meshFilter.mesh.bounds.size.z * transform.localScale.z;
}
else if (renderer != null)
{
hitboxSize.x = renderer.sprite.bounds.size.x * transform.localScale.x;
hitboxSize.y = renderer.sprite.bounds.size.y * transform.localScale.y;
hitboxSize.z = renderer.sprite.bounds.size.z * transform.localScale.z;
}
//hitboxSize.z = mesh.bounds.size.z * transform.localScale.z;
switch (body)
{
case InertiaBody.BOX:
{
float oneSixth = 1f / 6f;
float side = hitboxSize.x;
float numToSet = oneSixth * mass * side * side;
inertia.SetRow(0, new Vector4(numToSet, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, numToSet, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, numToSet, 0));
break;
}
case InertiaBody.CONE:
{
float radius = hitboxSize.x * .5f;
float height = hitboxSize.y;
float firstSecond = .6f * mass * height * height + .15f * mass * radius * radius;
float third = .3f * mass * radius * radius;
inertia.SetRow(0, new Vector4(firstSecond, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, firstSecond, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, third, 0));
break;
}
case InertiaBody.CUBE:
{
float oneTwelfth = 1f / 12f;
float first = oneTwelfth * mass * (hitboxSize.y * hitboxSize.y + hitboxSize.z * hitboxSize.z);
float second = oneTwelfth * mass * (hitboxSize.z * hitboxSize.z + hitboxSize.x * hitboxSize.x);
float third = oneTwelfth * mass * (hitboxSize.x * hitboxSize.x + hitboxSize.y * hitboxSize.y);
inertia.SetRow(0, new Vector4(first, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, second, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, third, 0));
break;
}
case InertiaBody.CYLINDER:
{
float radius = hitboxSize.x * .5f;
float height = hitboxSize.y * .5f;
float oneTwelfth = 1f / 12f;
float firstSecond = oneTwelfth * mass * (3 * radius * radius + height * height);
float third = .5f * mass * radius * radius;
inertia.SetRow(0, new Vector4(firstSecond, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, firstSecond, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, third, 0));
break;
}
case InertiaBody.HOLLOW_BOX:
{
float fiveThirds = 5f / 3f;
float first = fiveThirds * mass * (hitboxSize.y * hitboxSize.y + hitboxSize.z * hitboxSize.z);
float second = fiveThirds * mass * (hitboxSize.z * hitboxSize.z + hitboxSize.x * hitboxSize.x);
float third = fiveThirds * mass * (hitboxSize.x * hitboxSize.x + hitboxSize.y * hitboxSize.y);
inertia.SetRow(0, new Vector4(first, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, second, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, third, 0));
break;
}
case InertiaBody.HOLLOW_CUBE:
{
float fiveThirdsOverTwo = (5f / 3f) * .5f;
float side = hitboxSize.x;
float numToSet = fiveThirdsOverTwo * mass * side * side;
inertia.SetRow(0, new Vector4(numToSet, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, numToSet, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, numToSet, 0));
break;
}
case InertiaBody.HOLLOW_SPHERE:
{
float radius = hitboxSize.x * .5f;
// 2/3mr^2
float numToSet = 2f / 3f * mass * radius * radius;
inertia.SetRow(0, new Vector4(numToSet, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, numToSet, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, numToSet, 0));
break;
}
case InertiaBody.SPHERE:
{
float radius = hitboxSize.x * .5f;
// 2/5mr^2
float numToSet = .4f * mass * radius * radius;
inertia.SetRow(0, new Vector4(numToSet, 0, 0, 0));
inertia.SetRow(1, new Vector4(0, numToSet, 0, 0));
inertia.SetRow(2, new Vector4(0, 0, numToSet, 0));
break;
}
default:
{
break;
}
}
inertiaInv.SetRow(0, inertia.GetColumn(0));
inertiaInv.SetRow(1, inertia.GetColumn(1));
inertiaInv.SetRow(2, inertia.GetColumn(2));
inertiaInv.SetRow(3, inertia.GetColumn(3));
}
