@belfegor: Well, your help is one of the main reasons that made me able to accomplish that I'm still doing some improvement so I could upload a video when I finish.
In this screenshot, the sparks looks messed up, because it's getting generated pointing at random direction, then when it move it point at the UP direction (correct direction), this problem is much more noticeable when the particles are moving:
(I think the problem is be more clear in this screenshot)
I'm looking for a way to modify the code to make it look at the moving direction when generated.
So my question is: How do I make the particles generate while looking at the gravity direction?
Here is how I generate the particles (I need to update the following code to fix this problem):
D3DXVECTOR3 randVec = getRandVector(); particle.velocity += randVec * 4.0f; // 4.0f = How much spread
Here is how I render the sparks lines:
// D3DXVECTOR3 lineFrom D3DXVECTOR3 lineTo RenderSingleLine( currentParticle.position, currentParticle.position - currentParticle.velocity * lineLength );