Making Snow using particleflow+pwrapper in 3dsmax

                                       papayadigital@163.com

1.First,create a PF Source in the Particle Systems panel, and put it on top of your object. Here in the tutorial, I use a Torus Knot.

2,Under Create /Space Warps/Deflector, click the UDeflector.

The UDeflector is very useful because it can change any kind of mesh object into a deflector.

3 Pick the Udeflector in the viewport, and under the modify panel, pick the Torus Knot, leave the parameters as default.

4，Pick the PFsouce in the view port, under modify panel, click particle view.
Change the Viewport% to 100.0.

5,Here is the standard particle flow.

Right click Render 01(Geometry),and  click Turn Off, cause we don’t need to render the particles themselves.

6,Click Birth node, change the birth ends at 10,and the particle amount 20000.
But of course, it’s not necessary to set this high number at first. You can set it 5000 for example,
and change to 20000 or higher you if want in the end..
To make things easy, I’ll leave it 20000.

Now, you should drag a cache node from the depot to the first event.
Leave it under the Render node., that’ll make things faster.

6,Clicke Shape node and delete it (click the Delete in the keyboard),no need here.
Also delete the Rotation node.

  Drag a collision node in the depot and put it under the display node.
 

In the Collision panel, click By List and select the UDeflector01,and leave others as default.

7,Drag a Speed By Surface node to an empty spot under the event 01  to create a second event.

And wire the two events.
 Drag from the Collision output, the blue dot that by default sticks out to the left of the Collision test, to the second event's event input, which sticks out from the top, or vice-versa.

8,Click Speed By Surface, in the modify panel, change the Set Speed Once to Control Speed Continuously. I want the particles to continuously move on the object’s surface slowly. So
Set the speed 5.0,and Variation 12,you can set it higher if you want.
Change the Direction to Parallel to Surface, or the particles will go away from the object.

OK, almost done.

9,Set the current key frame at 22,let’s see what will happen.

Hmm… not bad.

10,Under Creat/Glu3d pouring system, pick the Pwrapper.
I hope you’ve installed glu3d,it’s very useful, especially the Pwrapper.

A Pwrapper Icon’s been generated , in the viewport, pick the icon(at 0,0,0).
In the modify panel, change the settings.

Under the Particle Objects, pick Add, and click the PF Source 01.
The settings depend on what kind of result do you want.
I won’t set the Detail too high, cause there would be too many meshes.

11,If you’re happy with the result, pick the pwrapper object  and Convert to Editable Mesh or Poly,  then you could delete the particle flow.(the particle flow and the pwrapper are damn slow)
You’d better do that in the end.

12.Then ,add a Relax modifier to the mesh, or  do it before you collapse the pwrapper.
The object looks much smoother right now.
And delete the useless meshes,

Now you can tweak the snow model in advance, for example, add a noise modifier or something…

13. It is one way to create snow, maybe not the best way, but sometimes, it works.
I hope you’ll like this tutorial, Thanks!

Download Max file here: http://www.cgdomain.net/snow.max