private void EmitNewParticle(ref Particle particle)
{
timeSinceEmit = 0;
particle.Energy = particle.StartingEnergy = Random.Range(minEnergy, maxEnergy);
Vector3 pointInUnitSphere = Random.insideUnitSphere;
particle.Position = Microsoft.Xna.Framework.Vector3.Transform(ellipsoid, transform.rotation) * pointInUnitSphere.x;
Vector3 velocity = Vector3.zero;
if (useWorldSpace && gameObject.rigidbody != null && emitterVelocityScale > 0)
{
velocity += gameObject.rigidbody.velocity * emitterVelocityScale;
}
if (rndVelocity.x != 0 || rndVelocity.y != 0 || rndVelocity.z != 0)
{
velocity += Random.onUnitSphere * rndVelocity;
}
if (tangentVelocity.x != 0 || tangentVelocity.y != 0 || tangentVelocity.z != 0)
{
velocity += Random.onUnitSphere * tangentVelocity;
}
if (localVelocity.x != 0 || localVelocity.y != 0 || localVelocity.z != 0)
{
//velocity += (Vector3)(-Microsoft.Xna.Framework.Vector3.Transform(localVelocity, transform.rotation));
velocity += (Vector3)(Microsoft.Xna.Framework.Vector3.Transform(localVelocity, transform.rotation));
}
if (worldVelocity.x != 0 || worldVelocity.y != 0 || worldVelocity.z != 0)
{
//velocity += (Vector3)(-Microsoft.Xna.Framework.Vector3.Transform(localVelocity, transform.rotation));
velocity += worldVelocity;
}
particle.Velocity = velocity;
if (useWorldSpace)
{
particle.Position += gameObject.transform.position;
}
particle.Size = Random.Range(minSize, maxSize);
particle.Color = renderer.material.color;
particle.RotationSpeed = Random.Range(minRotationSpeed, maxRotationSpeed);
if (randomRotation)
{
particle.Rotation = MathHelper.TwoPi * Random.value;
}
int x = Random.Range(0, textureTileCountX);
int y = Random.Range(0, textureTileCountY);
particle.TextureScale = new Vector2(1.0f / textureTileCountX, 1.0f / textureTileCountY);
particle.TextureOffset = new Vector2(x * particle.TextureScale.x, y * particle.TextureScale.y);
}
public void UpdateParticleColor(ref Particle particle)
{
if (doesAnimateColor)
{
float colorScale = 1 - (particle.Energy / particle.StartingEnergy);
float startIndex = colorScale * 4;
int iStartIndex = (int)Mathf.Floor(startIndex);
if (iStartIndex == 4)
{
iStartIndex = 3;
}
colorScale = startIndex - iStartIndex;
Microsoft.Xna.Framework.Color nonPremul = Microsoft.Xna.Framework.Color.Lerp(_colorAnimation[iStartIndex], _colorAnimation[iStartIndex + 1], colorScale);
particle.Color = Microsoft.Xna.Framework.Color.FromNonPremultiplied(nonPremul.R, nonPremul.G, nonPremul.B, nonPremul.A);
}
else
{
particle.Color = renderer.material.color;
}
}
private bool RenderParticle(Camera cam, int vertexIndex, int triangleIndex, ref Particle particle)
{
float size = particle.Size / 2;
if (size <= 0)
{
return false;
}
Microsoft.Xna.Framework.Vector3 pos = particle.Position;
if (!emitter.useWorldSpace)
{
pos += (Microsoft.Xna.Framework.Vector3)transform.position;
}
if (doViewportCulling)
{
BoundingSphere sphere = new BoundingSphere(pos, size);
if (cam.DoFrustumCulling(ref sphere))
{
return false;
}
}
vertices[vertexIndex].TextureCoordinate = new Microsoft.Xna.Framework.Vector2(particle.TextureOffset.x, particle.TextureOffset.y + particle.TextureScale.y);
vertices[vertexIndex].Color = particle.Color;
vertices[vertexIndex + 1].TextureCoordinate = new Microsoft.Xna.Framework.Vector2(particle.TextureOffset.x, particle.TextureOffset.y);
vertices[vertexIndex + 1].Color = particle.Color;
vertices[vertexIndex + 2].TextureCoordinate = new Microsoft.Xna.Framework.Vector2(particle.TextureOffset.x + particle.TextureScale.x, particle.TextureOffset.y + particle.TextureScale.y);
vertices[vertexIndex + 2].Color = particle.Color;
vertices[vertexIndex + 3].TextureCoordinate = new Microsoft.Xna.Framework.Vector2(particle.TextureOffset.x + particle.TextureScale.x, particle.TextureOffset.y);
vertices[vertexIndex + 3].Color = particle.Color;
//rotated particles
if (stretchParticles == StretchParticles.Billboard)
{
Microsoft.Xna.Framework.Vector3 particlePosition = particle.Position;
Matrix.CreateBillboard(
ref particlePosition,
ref camPosition,
ref camUpVector,
camForwardVector,
out m
);
Microsoft.Xna.Framework.Vector3 vertical = new Microsoft.Xna.Framework.Vector3(0, -size, 0);
Microsoft.Xna.Framework.Vector3 horizontal = new Microsoft.Xna.Framework.Vector3(size, 0, 0);
m.Translation = Microsoft.Xna.Framework.Vector3.Zero;
//Microsoft.Xna.Framework.Vector3.Transform(ref p, ref m, out p);
Microsoft.Xna.Framework.Vector3.Transform(ref vertical, ref m, out vertical);
Microsoft.Xna.Framework.Vector3.Transform(ref horizontal, ref m, out horizontal);
vertices[vertexIndex].Position = pos - vertical + horizontal;
vertices[vertexIndex+1].Position = pos - vertical - horizontal;
vertices[vertexIndex+2].Position = pos + vertical + horizontal;
vertices[vertexIndex+3].Position = pos + vertical - horizontal;
}
if (stretchParticles == StretchParticles.Stretched)
{
size *= 2;
Microsoft.Xna.Framework.Vector3 particlePosition = particle.Position;
//TODO make this work correctly, and add velocityScale functionality.
Microsoft.Xna.Framework.Vector3 vertical = -particle.Velocity;
vertical.Normalize();
vertical *= size * lengthScale;
Microsoft.Xna.Framework.Vector3 horizontal = -Microsoft.Xna.Framework.Vector3.Cross(vertical, camForwardVector);
horizontal.Normalize();
horizontal *= size;
vertices[vertexIndex].Position = pos - vertical + horizontal;
vertices[vertexIndex + 1].Position = pos - vertical - horizontal;
vertices[vertexIndex + 2].Position = pos + vertical + horizontal;
vertices[vertexIndex + 3].Position = pos + vertical - horizontal;
}
if (stretchParticles == StretchParticles.HorizontalBillboard)
{
vertices[vertexIndex].Position = pos + new Microsoft.Xna.Framework.Vector3(-size, vertexIndex * 0.0001f, size);
vertices[vertexIndex + 1].Position = pos + new Microsoft.Xna.Framework.Vector3(-size, vertexIndex * 0.0001f, -size);
vertices[vertexIndex + 2].Position = pos + new Microsoft.Xna.Framework.Vector3(size, vertexIndex * 0.0001f, size);
vertices[vertexIndex + 3].Position = pos + new Microsoft.Xna.Framework.Vector3(size, vertexIndex * 0.0001f, -size);
}
return true;
}
