It would really serve you well in future to properly phrase your question with as much information as possible - I had to guess that you were talking about Maya and guess that you want to bake animation. This is important not just for those answering you, but those searching for answers themselves.
The second result on Google for Bake animation maya paint fx animation gives me:
you can bake the animation of the tree after converting them into polygons in Maya.
To try it out:
-In a new scene create a BirchSpringHeavy tree from TresMesh in the visor.
-Modify>Convert> Paint Effects to Polygons.
-Select the main root birchSpringHeavy1Main then : Geometry Cache> Create a new cache.
-Select the leaves birchSpringHeavy1Leaf and cache again.
-Select everything the file>Export Selection and save it as FBX.
-Create a new Scene, import the FBX tree.
-Select the Root object the Geometry>Import cache and chose the xml file corresponding
-The same for the leaves.
Now you can see the tree using the baked animation.
I'm sure it makes you feel better about yourself, but condescending lectures are just childish. All that does is irritate people, and not just the person you're addressing--everyone who searches their way to the thread has to listen to it. Grow up.
Replies
The second result on Google for Bake animation maya paint fx animation gives me:
From: http://forums.cgsociety.org/showthread.php?t=860678
It is for a tree, but I'm fairly sure this would work for your grass.
Good questions = good answers. Don't be a lazy, selfish user - write properly.