Forgive me for a sort of basic question, but i just upgraded from Viz, so particle systems are new to me.

I saw in a demo, a while back, someone using (I think), a particle system to scatter rocks and trees, etc, over a surface, and he used a selection painting tool to define where the objects were being scattered.  This would be a hugely useful technique for me right now.  Can someone be so kind as to give me some getting started pointers on how to do this, or point me to a tutorial?

Thanks

Make a pflow source
Append a position object operator
Append a Shape Instance
Delete the Old Position Icon and Shape operators
Set Display to geometry so you can see your work.
add the ground plane of your shot as that postition object
go to your ground plane object make a sub object selection of where you want your grass, trees, rock what have you.
go back to the Pflow source
got back to your Pos. obj. operator
use the pull down menu to select selected (faces or verts what ever you chose as your selection)
delete the speed operator
make birth operator starting at frame 0 or 1 what ever you start on.
go to the shape instance operator and add what ever you want to scatter (make sure the pivots at the bottom of the object so say if it’s a tree the tree is above ground.)
Then come back to the Area forums and thank me by answering someone else’s post :)
finally have a great day and be sure to enjoy spring if your in the northern hemisphere.

-Carl_Braun
>C:/BRAUN

Look at the attachment if you have problems
If you want an array of say different trees and say rocks scattered group them and pick the group sub obects under the instance geometry section.

	Attachment
6729_IghvqTMawJGBem3WGeDc.zip

I am delighted to thank you for this, it worked like a charm.

Actually
Now that I have had a chance to work myself throuh all those steps, and play with it a bot (particles are totally new to me, htere is a lot to explore hre), it all works great
- thank you very very much!
EXCEPT
having selected a bunch of vertices to distribute trees onto, they dont seem to be limiting themselves to just where I selected - tehy are spread all over the mesh.

Any idea what I might be missing?

The Position Object operator has a Location group; from the pull-down menu, select the Selected Vertices option.

wade s

Max 8 (no mo) & 9 (solo) SP2
Win XP SP2, 3.7 Ghz, 3Gig Ram
Quadro FX 3400

That is working beautifully if I just do a normal sort of selection, but it does not appear to work if I use the brush selection, presumably because it is a solft select.  I like the brush selection option, because it gives a vaguesly organic shapre to waht I have selected, but I can achieve waht I need using a lasso selection instead.

Still, if anyone knows a way to do brush likke selections that are all or nothing, not soft, I would be interested.

Thanks

Oh, duh, the answer was right before my eyes.  Ignore my previous post.