Glank: Sound Effector in Practice: The Big Bass Drum

Photo of Joseph Herman

Instructor Joseph Herman

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  • Duration: 12:31
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In this video, we’ll see how the sound effector was used to animate the big bass drum.

The sound effector was used to animate the rotation of the mallet which strikes the big bass drum. Since we don’t need a lot of clones, we’ll use the sound effector on a fracture object. We’ll also see how to set up rigid body dynamics on the drum and modify the follow position and follow rotation amounts so that the drum reacts to the pounding realistically. We’ll also demonstrate how to turn off the all frames option during playback to keep the animation in sync with the sound in the viewport. Finally, we’ll look at how to use Xpresso to illuminate the ring of yellow lights around the rim of the drum to the sound of the big bass drum.

Music and found object instruments by Paul Rudolph.



♪ [music] ♪ - The first thing we're going to start with is the big bass drum, which I've isolated here to keep things simple. The bass drum was made out of an oil tank object, which can be found here. Before I do anything, I want to disable this all frames option. All frames is on by default, and what it does is it forces Cinema 4D to play all of the frames in the animation when you hit the play button. This can cause sync issues when dealing with audio, and the audio can sort of get out of sync with the animation in the viewport. By unchecking all frames, the sound and the animation in the viewport will sync up much better. As mentioned before, we'll be using the sound effector to animate the objects to the sound of the music. There are several ways to use the sound effector. You can use it on a MoGraph Cloner. You can use it on a fracture object. And there are some other ways you can use it as well. In this case, we'll be using the fracture object. So we're going to choose a fracture object. And we're going to drag all of these pieces right here, which is the base of the hammer, and the shaft, and the hammer itself. We'll drag all of these things into the fracture object. Now, with the fracture object selected, let's go to the MoGraph menu. Let's go to the effector sub menu and choose the sound effector. And there it is. Let's switch to Adobe Audition for a moment to talk about the audio. The music for this piece was created by a New York musical ensemble called Glank. They provided me with their song, broken into multi-tracks. So there's a separate track for each one of the percussive instruments they used. The drum uses this track. Let's solo it and play it. ♪ [music] ♪ The reason it was separated into different tracks was that so each part of the animation would be doing something different. So now what we want to do is import this track into the sound effector. So let's bring in that audio. To do so, click on the sound effector, and in the sound file area, click on the button and find that track. And here it is. Note that if I click on the fracture object, in the effectors tab, the sound effector is listed in it. Okay. Let's see what happens if we play the animation now. ♪ [music] ♪ Okay, we can see that the sound effector is having an effect, but it's not the right kind of effect. First of all, let's click on the sound effector and go into the parameter tab. And we can see that the sound effector is set to effect the position of the object. Well, we don't want that. We want it to effect the rotation. So let's uncheck position, and let's check rotation. And let's type in -50 on the banking rotation. Let's see what that does. ♪ [music] ♪ Seems to work pretty good. Obviously, we'd like this drum to react to the hammer hitting it. So let's right click on the oil tank, and let's go to the simulation tags and add a rigid body simulation. Let's also go to the hammer, this object up here. Let's right click on it and give it a collider body. Now what should happen is that when this hammer strikes the drum, the drum should react to it. Let's see if it works. ♪ [music] ♪ Well, you can see that's not what we want. And the reason that that's happening is because as soon as you add a rigid body tag to something, gravity has an effect on it, and the object just falls out of the frame. Let's rewind. To fix that problem, let's click on the oil tank's rigid body tag, and in the force tab, we're going to change the follow position amount to 15. Follow position tries to make an object that is effected by dynamics, maintain its original position. Let's see what happens when we set the follow position amount to 15. ♪ [music] ♪ Well, it seems to want to follow the position, but the rotation is completely uncontrolled. So, that's why we want to go over here, to the follow rotation amount. Let's try to set that to 25 and see what happens. ♪ [music] ♪ Like follow position, follow rotation tries to maintain the original rotation of the object. You can also increase the linear damping and angular damping to provide a little dampening on the motion of the drum. ♪ [music] ♪ For the next part of the tutorial, I've brought back some of the details of the set. If you notice, there are these yellow lights that go around the perimeter of the drum. I'd like to have these lights get brighter as the drum is struck. To do this, we're going to need a little Expresso. Let's make a null to put the Expresso on. So there's the null. I'll right click on it, CINEMA 4D tags, Expresso. To start with, we're going to bring the sound effector object into the Expresso area. And, on the output port, we're going to pass out the sound effector object. The next node we're going to make is in the motion graphics area, and it's called sample. What the sample node does is it lets you take in an effector, and it can ascertain values from it. One of the values it can get is the strength of the effector. So let's set this output port to be strength. Now let's drag in the drum lights material and set its input port to be luminance/brightness. So that will allow us to affect the luminance channel of the drum lights material. Now let's connect the strength port to the luminance/brightness port. And let's see what happens. I'll move this out of the way so we get a better view. And I'll hit return and press play. ♪ [music] ♪ So, it seems to be working pretty well, except I have one issue with it. For some reason, the lights don't seem to be getting that bright, even in parts where it's really loud. I'm going to make a new node here called the result node. This node basically takes the output from a port and displays its numerical equivalent right here in the Expresso editor. As you can see, there's a value of 0.6 currently being output from the strength port. Let's move to a different part of the animation. ♪ [music] ♪ Such as this part. And you can see that the result it 0.644. Let's go ahead to even a different part. ♪ [music] ♪ Here. Now it's all the way up to 0.775. And that's probably the brightest it's going to get. The luminance channel, in the drum lights material, takes a value going from zero to one, zero being no luminance, and one being full luminance. So these values, at the brightest, are probably going to get to about 3/4 of the way. Therefore, I'd like to make a coefficient to help boost these values so that they get closer to one before feeding them into the luminance/brightness input port. To do this, I'm going to make a new math node, which can be found under the calculate settings. Here it is. For the first input, I'm going to feed in the strength value. Let me get rid of this wire right now. For the second value, let me move this out of the way, the multiplier, well, let's say, 1.33. So basically what I'm doing is taking this amount, and I'm multiplying it by the value of 1.33. Don't forget to change this value, the type of mathematical operation you want, which is, in this case, multiply. If I had left it on add, it would just add this value, and that's not what we want. So now let's go ahead and let's copy this result node, move it over here, and see what the value is as it's coming out. And the value is 1.031. It's okay if it's a little bit over 1. So now let's go ahead and feed that output from the math node into the luminance/brightness. Immediately you can see how these got brighter. So now if I play back the animation... ♪ [music] ♪ You can see that the luminance values are much brighter now. Let's move on to the next component of the animation.
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