Join Ellery Connell for an in-depth discussion in this video Particle generation tools, part of Modeling for Product Visualization in MODO.
In this video, we'll look at how to add particles onto our existing geometry. Now, there are a number of ways of doing this, and there are some that are going to give us more even, randomize particles and then some other ones who will give us more control over the actual particle placement. So let's start with a simple item. Let's go up to the Items here We'll add item, go down to Particles, choose Surface Particle Generator. So once I add a surface particle generator in here, you can go into the properties, go to the source surface and then choose the item you want to attach this to. So let's choose splash and by default it's going to space them an average of 100 mm a part which in our scene is pretty far apart. So what I'm going to do is drag this number down. And as I drag this down, you'll start to see particles appear. So let's pull this down even more and you'll see these particles start to appear, and then they, they'll start to get a bit more dense as this number goes down even farther.
Now you can also take the Density Multiplier and increase that, and it's going to multiply based off of the distance that you have, but they're really just two ways of doing the same thing. Now you can also, if you like the number of particles but you're not real happy with the placement You can very easily go in and change the seed, and it's going to keep a similar amount of particles, similar randomized spacing, but then it's just going to kind of roll the dice once again, and put the particles back out there. One thing you might notice as you really decrease this average spacing, the particles start to get really close together.
But when you hit a certain point, you'll start to get big holes in where the particles exist on your geometry, like that. So you can see, I've got particles pretty much everywhere. But they're really only sticking to some parts. So let's decrease this a little, so it's not quite so pronounced, there you go. Now you can see probably a little more than half the area has particles on it. And and there's these large chunks of space where there are no particles. Now, the reason for that is, by default, there is a particle limit of 10,000 particles within each individual particle surface generator.
And the nice thing is that is very simple to adjust. Down at the bottom, Particle Ceiling, you can see that here it's set to 10,000, and so in this case, even if I increase this to 15,000 you'll see that those areas fill in. And then we were left without the gaps. Since particles are going to show up on screen no matter how far out you zoom, it's oftentimes a lot easier to zoom out for a second to get an idea of your particle placement. Especially if you're worried about setting the particle ceiling. So if, for example, I take this down to something like 11,000. See, I still have these holes.
And I can more easily see those holes if I zoom out. So this can allow you to do a better approximation. Let's go to 12,000 and that actually fills out everything. So in this case, all I need is 12,000 particles in this case. And that will cover the entire area. Now, one issue that you might get with doing particles like this for something like a splash, is that it's going to give kind of this even slightly randomized blanketing of the particles all over the place. So really this might not be the best thing for doing splashing water.
Now, if you have a lot of them all together, you might get some nice rippling in there and that could work pretty well as far as using your water, but oftentimes this kind of particle placement with the Surface Particle Generator Is more geared towards doing things kind of like droplets on a can itself. So, if I go in here to my Surface Particle Generator and I change my source surface to can, which is that lead can, you see that it puts all these particles all over the can. And now this could be something like, kind of the water droplets that you might find on a can.
And you could do a couple of different ones of these as a side note. You might want to have one where the average spacing is higher, and those will be your larger drops. And then you could have a duplicate surface generator that's looking at the same mesh but a much decreased average spacing. And this one will give you something more of those kind of fine, misty droplets that you might find on the cam. So, that will give you good randomized particles. So, let's look then at other ways that we have of generating particles and the main way is going to be painting particles. So, let's go over to the Paint Tab.
And underneath all of the sculpting and painting and hair, you'll notice that there is a Particle tab. And this will give you some options for working with your particles, but at the very bottom, you'll see Particle Paint. And that will allow you to actually go in and paint particles all across the surface. So I'm going to turn on 3D brush and create particle mesh, and click and drag. And now as I do that if I look underneath splash here, you'll see that I have particle mesh. And that's going to be where I actually see my individual particles. Now, if those particles don't show up you might need to come in and make sure that you have show vertices enabled.
And then there you can see there are my particles. You can see since I did a stroke of particles in this empty layer here, they didn't have anything to stick to, so let's just back up one level, select the actual splash layer here, and then if I paint on this, it'll see that the particles are actually sticking to the background mesh, except there I had some Still remaining from that previous paint stroke. So, this is going to be a good way of getting more spatially aware particles, because you are going to generate their actual position.
So, let's go back up here to the splash and you can see as I paint on these particles, I can put them just in the areas where I want them. So, sometimes it's a good idea to use something like the surface particle generator to get some of your particles in place. But then you can go back and get more of them by adding in kind of these more specific ones in areas where you need them. As you can see this is lifting up nicely here off the surface and just giving me a general good placement. Of particles, and I can even take this particle mesh outside of the parenting here and just put it up in there.
And move the splash up while we're at it. And now I can hide this splash, and you can see that this particle mesh is still there. So, I still have these randomly placed particles that are random based off the brush area, but have allowed me to paint them in and get them concentrated where I want them. Now, in this case there are a bunch that are underneath the ground. So, I'm actually going to do one thing here to clean this up a little bit, because I may want some more of these particles to kind of land on the ground. So, I'm going to go over to Vertices, and I'm just going to right-click and drag underneath here just to get all the particles that are under the ground, and I'm going to use my Scale tool, just the action center to the origin, and make sure that Negative Scale is off.
And I'm just going to pull these in, and kind of flatten them out and actually I'm going to move them up just a little bit too to make sure there kind of above the ground plane of my existing environment and now that's going to give me my particles kind of puddling up on the floor. So, here again lets go and make sure that I have show vertices turned on for this layer and there you go. So, now I have my particles If I looked at this from kind of a front view, you can see that we're already getting the idea of these kind of splashing up to either side, and then a little bit in the front where these cans have hit the ground, and also you can see the particles in the background on the can that we've used in the surface particle generator.
So, using those couple of tools you can pretty quickly add in particles to your scene to simulate splashes or blobs or any kind of liquids or things that might be Flowing in more dynamic in your product visualization shot.
- Intro to 3D for product visualization
- Benefits of polygonal modeling
- Polygonal modeling techniques
- Modeling with SubDs and PSubs
- Sculpting concepts and retopology
- Setting the scene
- Building geometry for particle generation
- Particle generation tools
- Using blobs