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3D TUTORIALS

MAKING EXPLOSINGS WITH COMBUSTION by Pĺl Vĺgsćther Karlsen

Ok, it's time to become a terrorist. Put on your ski-mask and take a look at how you can make explosions. Of course, this is just in 3D Studio MAX, so don't get your hopes up about the local bank.

Jokes aside, explosions are cool. You see them in almost every Hollywood action-movie, and all kinds of TV-shows. So why can't you make them yourself? With 3D Studio MAX and the plugin Combustion by Rolf Berteig there is no reason why you shouldn't take part of the fun. I will first go through the basic steps to create the explosion. At the bottom of this page, you will also find some helpful tips on how to animate your explosion.

First of all, some minor notes. For this tutorial you need the plugin Combustion, avilable from Kinetix. This is a free plugin, and you can download it from Kinetix' own homepage at http://www.ktx.com/. Second, we need to use Space Warps. The Bomb space warp is perfect for this, so we're going to use that for making the mesh. This method shows you how to blow up objects and make the fire/explosion inside it. Just follow these steps.

Step 1. First of all, you need an object to blow up. Due to the way the Bomb space warp works, this object needs to have a high number of faces, or the faces must be small. Therefore, a [1x1x1] box will not look too good. If your object has many large faces, you can use the tesselate function in the Edit Mesh modifier to split up the faces. For this tutorial, I've made a lofted object, a hash (#), just as an example. Here is the "still-in-one-piece" object:

This object is lofted, and lofted objects often have a high number of faces. This one has 7296.

For your object, you can choose whatever you want. Just for trying this out, you can for instance use a sphere.

Step 2. Ok, it's time to do some exploding. This step deals with blowing up your object using space warps. Space Warps can be found on the Create tab:

Click on the Space Warps button to bring up the menu.

Choose Bomb on this menu, and position it in the middle of you object.

Important note: The bomb space warp is indicated as a small "pyramid". The explosion goes from the middle of this and outwards over a series of images. This mean that you can also position the bomb to the side of the object, and it will blow the object to pieces, and the pieces will move away from the bomb.

Now, when you have positioned the bomb where you want it (mine is in the middle of the object), it's time to link it to the object. This is done by clicking on the Bind to Space Warp button in the main interface of MAX (on the top):

To use this function; click on your object and hold, drag onto the Space Warp (the bomb) and let go of the mouse button. The bomb is now assigned to blow up your object. Now, as you do this, you might wonder why nothing happened. Well, it did. It just doesn't show in the first frame. To see how the explosion affects your object, go to frame 10 (or a frame close to that). Now you can see that the bomb has in fact blown up your object:

Here is the "blown-up" object (frame 10).

Well, this doesn't look so exciting. The explosion looks to regular and unnatural. To avoid this, you'll need to select the Bomb and modify it. You will then be able to modify how the explosion behaves.

The various parameters for the Bomb.

Strength: The strength of the explosion is set here. The higher value, the farther and faster will the pieces fly.

Gravity: With gravity, the pieces will fall down. The gravity works in the Z-axis, and you can also have negative gravity.

Chaos: An explosion is never uniform. That's why you want to add chaos. A value if 0 (zero) here will make the explosion totally uniform.

Detonation: Sets the frame the bomb detonates.

Here is my object blown up with the parameters shown above. Note that I have zoomed out a bit to see all the pieces:

Here is the object with my parameters (frame 10).

Ok, you have now blown up your object. The next step is to add the actual explosion.

Step 3. For this step, I asume you have downloaded and installed the Combustion plugin. To add the explosion to your scene, you first have to create the Atmospheric Apparatus for the Combustion. This can be found on the Create tab, under helpers:

Select Atmospheric Apparatus.

Now, select Combustion and create the apparatus. The Hemisphere check-box should not be checked. Now you can create the apparatus. This is shaped like a sphere, and should be positioned so the center is where your Space Warp is. This apparatus itself doesn't generate any flames. To do this, go to the Rendering menu and go to the Environment modifier window. In this window, select (under Atmosphere) Add and select Combustion. You will now see the various parameters for the Combustion plugin.

Here are the parameters I used.

Pick object: Select the apparatus.

Fireball/tendril: Select fireball. Tendrils are regular flames. and you want the balls for this one.

Flame detail: I set the detail to 4. This parameter lets you (big surprise) regulate how detailed the flames are.

Density: This is by default at 15. I use 10 so the outer parts of the flame doesn't cover the pieces entirely.

On the Explosion part, check the Explosion-box. Also, I use 2.0 for the fury.

Ok, now you're ready to render this. Obviously, you have to test-render this along the way to try out lights, explosion parameters, flames, apparatus-size etc..... Before you try this, here are some tips:

1. The object you blow up should have a high number of faces.

2. Try different values for the Chaos in the Bomb parameter box. A value higher than 1-2 is preferable.

3. Try out the size of the Combustion Apparatus; find out how big it must be to look credible (this also depends on the size of your object).

That's it! Happy exploding......

Here is the finished render. Of course, this doesn't look totally like the real thing, but it is created with basic MAX features.

Animation

Ok, I promised to give you some tips on how to animate this. Since both the Bomb Space Warp and the Combustion can handle animation, this is actually easy. As I said earlier, you can set which frame the Bomb detonates. This can therefore happen whenever you want. The next step after you set the start for the detonationis to adjust the Combustion Explosion to coinide. You have to experiment with this, since this also depends on the size of the object. You want the flames to show up when the object explodes. You set this in the Setup Explosion in the Combustion window. Here you can set the start and end of the explosion. And that's it. Try this out, and find out which values you need. Anyway, here is an overview of some of the frames in my example:

Here are some frames in the animation.