 So you just want to make a sandstorm, not a problem. DT just means smoothness, the higher the value, the more choppy the effect will be. Gravity direction X, Y, and Z just determine what direction the particles will fall. X determines left and right, Y determines up and down, and Z determines forwards and backwards. The bigger particle life, the longer each particle will stay alive. Spawn angle X and Y, change the direction and angle the particles start from. X makes the particles start from a more horizontal angle, and Y pivots the rotation from the top. The higher spawn direction random, the more random the particles will go all over the place. Spawn distance is how long the particle has to travel before it reaches its destination. The higher spawn rate factor, the more particles get instantiated. The higher the spawn speed, the faster the particles will travel. The more turbulence power you have, the less straight the lines become. And the more turbulence scale, the more the lines start to wave back and forth. I personally don't use these sensitivity settings, but be careful because when either one goes above zero, the brush seems to stop working. The higher the opacity, the more the fade. The higher the fade opacity random, the more unpredictable the fade becomes. The higher fade size, the more the ends of the particles shrink as they fade. The higher fade side random, the more unpredictable the size of the ends of each particles are as they fade. The less friction you have, the more the particles will slide down the surface. Next we have global wind, which of course does all the usual. X determines left and right, Y determines how much they resist gravity, and Z determines forwards and backwards. Speaking of gravity, if you want to control it directly, you can make it weaker here, or stronger like this. If you want it to look like the particle was tossed from a direction, you can make it inherit velocity. And I believe this is dependent on the strokes of your mouse. If you want to make the inherited velocity more unpredictable, increase this. Again, I really don't use the normal factor. The higher the particle life, the longer each particle will last, and the higher particle life random, the more each particle will die at different times. The bigger the spread, the more sporadic the direction each line becomes, the more turbulence power you have, the less straight the lines become. And the more turbulence scale, the more the lines start to wave back and forth. Hope that helps and as always, I hope you have a fantastic day, and I'll see you around.