Welcome to using objects with particle systems.
In this video you will learn how you can place hundreds of objects easily and fluidly using the particle
system.
We're going to control the distribution of particles using the weight painting and virtex groups and
turn off outlines when they start to clutter the view.
So let's hop straight on over into blender.
Okay so we'll start off with the outlines in fact since we've got some good examples in front.
Now if you followed through on the last challenge you'll notice I turn them on and off.
So this is where I officially after the event of course tell you about the outline so when you start
to have hundreds of these in our scene it's going to be quite difficult to actually see what's going
on.
If I get very cluttered very quickly now in the propertys pain the nke on the 3D view when you scroll
down there will be an option for display and sometimes it's toggled in or out but there's simply a checkbox
here that you can use outlines selected or not and you can see straightaway that it's great to be able
to see what's actually going on and how it looks.
Now the other thing that I noticed as I was working on this is that this model itself is quite high
in its polygon count.
So let's see if we can sort that out before we start putting hundreds of them into our scene.
So let's have a look at the modifiers here and I'm going to use the decimate modifier similar to how
we made our low poly porn over in the chest section.
Now when we use unsub divide for this one and we can see I've got 259 faces and if I turn on the outline
again we can see that most of them are on these small blades of grass crisscrossing one another.
Some I'm going to increase these iterations and it looks like the lowest number of faces I can get is
around five iterations.
Yeah.
And 23 faces interestingly.
You get less number four.
Okay.
So let's see what it looks like number four.
Again I'm going to have to turn the outlying isolated off.
Now if I was really close to the grass would I notice that.
Maybe not.
Now it gets a bit funny here it goes a bit wobbly.
Let's see how it looks at three and it's a tiny bit smoother.
I think we can actually get away with it at four houses were very rarely going to be this close to the
grass and if we are going to be lots of other grass around as well that's going to disguise any of these
nooks and crannies and kinks in the blades of grass.
So I'm going to do that and apply my decimate so I've dropped this massively down from the number of
faces it had and obviously the number of triangles it had as well.
Much much neater.
So let's play about with adding objects into a scene.
Now in order to do that I'm first going to save my file and I'm going to demonstrate the whole object
putting into a scene not in our bunny scene at the moment so I'm going to go ahead and open up a new
file and reload the start up file.
So let's go ahead and play with our cube here.
I'm going to move it to one side and I'm going to create a cone so we're going to have a cone and Cube
as our two objects that we're going to play with and use the particle system on.
Now I'm going to select both of them and put them on Lay five let's say So they're just out of the way.
Whoops I've just moved to layer five rather than moved them to layer 5.
But let's work on left.
Anyway.
And that's what you'll probably want to do with most of the objects that you want to use with any particle
system move them to their own separate layer so they're just out of the way and you can turn them on
and off really quickly.
Right.
I'm going to add a ground plane.
That were going to work with.
I'm just going to scale it up and probably just subdivide it a couple of times or hop into edit mode
and subdivide and I'll just make it a little bit uneven as well that's probably a bit too much geometry
but it will do for this example them.
Paul that's up there.
Spread it out and make a big hill there so we can watch things go over and I'm going to make a less
of a big hill though.
I'm just going to play about and you can obviously make your touraine how you want to make it so that
looks pretty good for the moment.
For our example I don't wanna hate.
Wrong one Swan and move it down.
No we get so lots of lots of geometry going on there a lovely smooth train.
In fact it only will be smooth if I turn on smooth shading.
So there we go we've got a basic train that now we can start putting our mesh objects on.
So let's start by adding a particle effect to this ground plane.
So I'm going to click on the particle's option here and create a new particle system.
I am going to start with the cones because it is important that I show you something that happens with
objects.
It may not happen with your textures since textures have y as facing up the particle systems also have.
Why is facing up.
So let's go ahead and create cones.
I'm going to call this one Cone's as well so we know when we can borrow it in a bit to apply it to our
cubes as well but we're going to set up one first of all it's going to be of type hairs and we can see
the hairs now growing out now.
We can replace those hairs with objects.
Now I know with the size of Cuban probably going to have to turn down the number that we have some just
going to turn it down to maybe 50.
For the moment.
And that also keeps our viewport nice and quick.
We can always change this later.
Now the hair length when dealing with objects you'll probably want to set the hair length to one and
then scrolling down under.
All Where is it hidden under objects so we select objects and the size here set that as one.
Now when that's one and this hair length here is one.
Your object will be the size that you created it rather than some random size in between.
That's always very useful for making sure that the scene is laid out as you were expecting it.
It's caught me out no end when I've not set these two to one obviously.
Feel free to change them afterwards to your heart's content but that's a very good starting point.
So now the object is selected.
We can go in cool actually going collect or go and pick the cone.
So it was pointing up on this layer here and on layer 5.
It's not it's O K or it looks like I haven't moved my justice.
I went to layer 5 a month press m and then moved to there 5.
Never mind.
But here we have a problem.
They're all laying on their side and we don't want that.
And that's because why is up as far as the particle system is concerned.
So we all we simply need to do is rotate our original cube around so we can enable both of the layers.
Now I've got to find that original Cuban I'm going to do that in the rather than playing hunt.
Kubic keep saying cube cone.
Rather than playing hump the cone.
I'm just going to select it in the outliner.
And I'm going to rotate it and let's rotate it around the y axis.
I'm sorry to have problems rotating it's rigour is rotating.
Ah yes of course this has caught me out no end of times.
On the plane itself we need to inherit the rotation.
So let's turn them both back on and see what happens when we click on rotation.
They rotate round brilliant.
So let's just undo what we've just done with the rotation.
There we go.
So back to here.
Back to plane back to rotation.
Make sure that's turned on over to the cone and let's rotate it in the y axis and see what happens.
So that looks like 90 90 degrees in the y axis sorts that out and makes it right obviously because we've
got some hills here some of them will bit a slight angle because they follow the curvature of the ground
that you place them on.
So now that we've done that those look quite small.
And you're thinking oh Mike I think you said if I set both to one they'll be full size.
Well they are full size.
It's just that half the cube is underneath.
And that's to do with its origin.
So if we go to the cone itself I keep saying cube if we go to the cone itself and the actual cone rather
than anything else.
Let's hop over to this player here.
Click anywhere on the base with the left mouse button and that'll set the 3-d cursor and then we can
just simply set the origin to the three cursor and see how that looks when we go back to this layer.
Excellent.
Now they're all on top of the surface.
Now you can play with all the particle stuff that you've done before so you can go in an ADD children
and if you do add children I would suggest they were interpolated So let's go to the children's section
here and do interpolated and they will follow the curvature of the ground that's a very spiky ground.
Now you won't want to stand on that.
And of course you can play with the uniform and loads of other things to your heart's content so you
could build up grass like this if you wanted to.
Well that's another way of generating the geometry.
Now one final thing let's turn off children for this moment in time so we can see what's going on.
Let's go and add another particle system so I would always recommend if you're using one particle system
and you've got loads more that are going to be similar that you get one of them right.
To begin with.
Because we can borrow those settings with a new one so that sets up a new particle system and called
it kubes.
And if we go here and we are talking about cubes this time we can borrow the currents.
Now we need to make it unique by clicking on this number.
Otherwise anything we change down here will change both of these particle effects.
So let's go down here and press the number two.
It changes to cone 0 0 1 and I'm going to rename that immediately kubes.
Now it looks no different at the moment because we do need to scroll down to the object and change it
to cube.
And you can see here that we've still got the same problem with it being half half.
I'm not going to sort that out at the moment but you can see that all of these objects are placed in
exactly the same location.
Now the way you change that scroll up and change the seed and the seed will change its placement.
Now that's great for randomizing things and making sure they don't all appear in the same place especially
if they've got the same number of admissions.
Another way of changing it is to change the number of emissions that are going on.
And eventually that will shuffle.
But it does still have some on top of one another.
So again changing the seeds will be the easiest way to make sure that they dont overlap right on top
of one another.
So the one final thing just like with the bunny you can use weight painting as well.
So say we wanted only these.
I will get my teeth back in the cones to be on the hilly parts of our of our mesh where we would make
sure the mesh is selected.
We go to the object data properties over here and let's scroll down with adverts group and I'm going
to call it kones on Hill.
It's always good to name it round this way and then immediately switch into white painting.
I'm going to turn off our particle system so I can see what's going on with the eyes there.
And so we've got these two hills so I can paint on that hill.
I can paint on that hill and I probably have to spin round and paint the other side of the hill as well.
And then I'm going to reduce or increase the size of the brush and reduce it strength down to 25 percent
or thereabouts.
Yeah that's fine.
And I'm just going to go over there.
Over here over there.
There once more.
There we go.
So that should help control the distribution of our of our cones and limited to only these areas leaving
the blue area clear.
So let's turn them back on and the first thing you say is all the Keeps haven't moved.
But remember the particle effect which is and this scroll down and changed the density setting under
virtex groups the density here to kones on Hill.
Oh that's great.
I didn't check what I was doing.
I have cues on health.
I was right when I said Dubes the first phone round I'm going to do remember which one you're selecting
when you're moving things about.
Of course I can scroll down and this cones on here I can just remove that.
Go to the cones themselves scroll down and click on gowns on Hill.
There we go.
So now the cones have moved to the Hill.
And if I turn off the cubes themselves to here we can see that they're distributed more in the red areas
than they are in the green and light blue areas.
Perfect.
Now armed with that knowledge I've got a challenge for you guys.
I would like you to plant some grass create a particle system for each grass mesh object and see your
landscape with grass.
Use low quantities at this stage.
Now might not look great but you don't want to slow yourself down when prototyping and use your texture.
Plants that we've made spidering Lee through out the environment set the ground colour to create a ground
material.
I suggest a diffuse brown colour and reiterate your scene lots and keep your samples low ash you go
and remember control and B to set a render border in the camera view to limit where your rendering said
to give you some more suggestions.
Turn off each particle system as you go for speed and seeing how each individual particle system looks
and then finally when you render the scene there is a good chance they will take a long time.
So keep those samples and resolution low intil you are happy to turn them up for fine or renders.
So to give you an idea of what I mean when I was prototyping I have grass that looks like this and you're
going well.
That looks horrible and grainy.
It's supposed to it's a prototype that took about 45 seconds or something along those lines to throw
out.
And I believe my samples were set to 5.
I didn't want to wait ages I just want to get an overview.
I keep iterating that and again I then mucked around with the grass and got it looking a bit more natural
and I ended up with this.
And again it's at five samples and when I looked at my rabbit's eyes when oh hang on a minute I have
I can see.
I can see the bit is supposed to be covered up.
You know we didn't model the lakes to keep it nice and simple but that looks like a levitating magical
bunny at the moment wishes certainly isn't.
So I then set a render border up so I could focus on that small area and make sure it comes out correctly
during the render and then and only then when I was happy with everything and set everything up did
I hit the render button at a higher sample rethink I picked 75 for my samples here and as you can see
it looks pretty good.
So go ahead and pause a video and go and plant some grass across our landscape.
Now I'm not going to be able to show you my solution in this video so that will be in the next lecture.
So once you've done remember to share in the discussions your solution to this.
I'd love to see them and I will see you in the next lecture.