Subtitles of the Movie

In this movie the last one in the Hair Section, we'll take a look at Simulation. And by the way, if you wanted to see a more completed version of the Giraffe Hair Shader we were working on in the last movie, just open up the Carrara File 1407.car and you'll be able to take a look at some other little tips and tricks I did to bring some resolution to that darkness of that Hair Shader that we had. When would you want to Simulation? There's two times. Obviously with animation when you're doing animation and want your hair to interact with the scene and any motion in the scene, but you might also want to use it for a still image if you have a force generator in your scene; something we haven't looked at yet that we'll look at in detail later on. Case in point, if you had a still scene but you wanted a character's hair to be blowing in the wind because they were on a motorcycle or car and having that hair interact with another person, another object around there, you would want to use simulation in that case as well. Now, this isn't the Animation Section so I've kind of put together an animation so you don't have to watch me quickly speed that together, but let's take a look at a couple features that I have built into this. I'll select the Hair Object right here. We're in a small scene so the hair length is six. I'm going to change the size to medium and nothing updates here but it does at render time. Hair is one of those things that doesn't really exist until render time. Under the Hair Group I'm leaving it at the default 5,000. There's a couple tricks to know with simulation that pay off. One is that if you're running a standard frame rate for television, you're at 24 or 30 frames per second; you can run your simulation at less. In this case I have mine set for 12 frames per second. This allows the simulation to complete much faster. Now, this is a really simple one. There's no additional effects done with the shader. There's no special forms that it's trying to keep that we set up in the Hair Room; really basic, so this one will go real quick. However, when you're dealing with a full head of curly, human hair, simulations can take a little longer and reducing the file or frame per second is a great way to cut some time off of that. The stiffness has been changed to 11 percent to the root and this will allow the hair when I drape it to hang down. The shape, I haven't given it any shape reinforcement. If we had curled this hair for whatever reason, we can boost the shape and have it hold that. That would add to the simulation time. I haven't done that here but that's something you could do. OK. Let's hop into the simulation. First there's two things; one is I want to drape the hair and since it's so simple I don't need a full 100 iterations. But this will allow the hair to start in a relaxed position. So we see the guide hairs relax, the hair is all down to the ground. If I wanted, I could go ahead and hop into the actual Hair Room and use that Push Feature to get it away because, well, it looks like it has collided with the actual object. So let me do that. I will Select Everything and then simply use the Push Tool; not the Straighten Tool, the Push Tool. There we go. And that will push it out just a little bit and we'll come back into our Assembly Room and now with the hair selected I'll come back to Simulation and choose Simulate. It will run through the animation real quickly and then do its thing and let the hair wiggle. That fast, that easy, the simulation's done. Go ahead and save the file here. We'll do a quick render. I've already set this up to render somewhat small so that we can see it done in our lifetime. The last frame and I noticed it looks like I forgot to do something. Smart guy here didn't enable Collision Detection. We'll, let's go ahead and loop this animation and you can see the hair doing its thing. We also see it going through the sphere a little bit but there's what the simulation does. It calculates what's going to go on with the hair at render time. You would use it when you use Forces or an actual animation in your scene. In our next section we'll take a look at a very fun capability of Carrara: Replicators.