Welcome to this Animated Nuclear Explosion Tutorial

I assume you already have the basic common knowledge of 3D Studio Max, so i wont enter into tedious explanation and will give you only the main steps.

Create the Mesh that will define the shape of your explosion, in this tutorial it is a nuclear explosion, though any shape can do it. Don't add any sharp details to this mesh, must stay simple.

When it's ready, apply a meshsmooth on it, iteration=1. This will round your mesh and give it only one smoothing group. You may also add some push modifier before the meshsmooth with a small negative value because of the displacement that will take place in the next steps...
Finally Add the Disp Approx modifier and keep the Low settings.

Now we will create the materials, which will give the full dimension of the explosion. First assign a default standard material to your explosion mesh. Name it XploYellow (or anything explicit) and set the diffuse color to some orange yellow. Now come the important part : Add some Cellular map to the displacement channel of this this material, and set parameters like in the screenshot.

The Cellular map is very powerfull but also very expensive in process time, especially if you raise the Iteration parameter when fractal is active. Make sure you have the correct colors, the grey's value is 75 in my example, and that the coordinate Source is World XYZ. Then put the displacement value to 25 in the root rollout of your material. If you launch a render, you should get something like this. If not, try to move a bit the Displacement value, and the size value of the Cellular map.


When you're satisfied, copy the cellular map that was in displacement to the diffuse slot of your material, and set the colors like this :
OrangeRed H:10 S:255 V:255
Yellow H:30 S:150 V:255
AlmostWhite H:35 S:35 V:255
Lower the Spread value to 0.4 and raise the Fractal iteration to 4.

Finally Add a gradient map in the last color slot, select Planar from Object XYZ in Mapping: and put exactly the same color in the 3 color slot of your gradient map as in the third slot of your cellular map (H:35 S:35 V:255) and then raise the Output Amout of this gradient map to 1.5 (the output amount is in the output rollout). Put the Self-Illum value of your material to 100. Your explosion should now look like this :

Your first material is ready, it will be the 'head' of you explosion. Now we will copy this material into 2 other materials. Name the second one XploRed and set its diffuse color to some OrangeRed, and name the third material XploGrey, and set its diffuse color to grey.
Now set the colors of the Diffuse Cellular Map of XploRed to :
Brown H:10 S:255 V:100
OrangeRed H:10 S:255 V:255
AlmostWhite H:35 S:35 V:255
Keep the Gradient Map in the third color. Raise the Spread Value to 0.75. Now copy the Cellular Map that is in the Diffuse Slot to the Self-Illumination Slot of your material. Assign it
to your explosion, you should have something like this :

The XploRed material will be for the center of the explosion while the XploGrey will be for the smoke around. In the XploGrey material, change the colors of the diffuse Cellular Map to :
LightGrey H:0 S:0 V:125
DarkGrey H:0 S:0 V:75
DarkRed H:10 S:255 V:165
Remove the Gradiant Map
in the third color. Raise the Spread Value to 0.75. Copy the Cellular Map that is in the Diffuse Slot to the Self-Illumination Slot of your material, and change its colors to Black, Black and a H:0/S:0/V:175 Grey. Assign XploGrey to your explosion, you should have something like this :
Here we go, the materials are ready,
Since the Cellular Map is a procedural set to World XYZ, it doesn't need any UVW coordinates to be applied correctly, though we will need some mapping for the correct mixing of the 3 materials. Select your explosion mesh, click on "Editable Mesh" in the bottom of the stack (must now be yellow though) and apply to it a cylindrical UVW Mapping that is oriented vertically. Then apply another UVW Mapping but this time you have to change the Map Channel to 2, otherwise your first mapping will be lost. Set this second UVW map to planar, oriented horizontally. These UVW Map should be between Edtiable Mesh and MeshSmooth in the modifier stack, if not move them...
Now that the mapping is ready, lets prepare the Mixs. Assign a non-used material to your explosion mesh, check Show Map in Viewport and put a gradiant Ramp in the diffuse slot. If not yet, put your viewport in shaded mode, you should have your explosion mesh like a rainbow (except if you work with max 5). Change the Gradient Type to radial, and change the colors as white on the left, black on the right, and 2 more sliders in the middle : white (left one) and black (right one). Now move the middle sliders so you have something like in the screenshot.

Do exactly as in step 3.2 with a new non-used material, but this time change the Map Channel to 2 and use a Linear Gradient Type. Try to get something like in the screenshot.

Now we will create the materials that will blend the XploYellow, XploRed and XploGrey. First you'll have to click-drag the two last gradient ramps you made from the materials to another non-used slot of your material editor so they can be accessible later (if it ask for Copy or Instance, select any, it doesn't matter). You may want to display more than 3*2 material slots for this operation.
Select a non-used slot and click on Standard so you can change the Material Type. Select Blend. Discard the old material. Name this material BlendRed/Grey and click-drag the XploGrey material in the first slot (select instance), the XploRed in the second slot (instance as well) and the Radial Gradient Map in the third slot (instance again). Apply this material to your explosion mesh, you should have something like this :
Create another Blend Material from a non-used slot and this time click-drag XploYellow to the first slot, BlendRed/Grey to the seconde slot, and the Linear Gradient Map to the last slot. Assign this material to your explosion mesh, you should have something like this :

The Materials are ready and Assigned !
First of all, to be able to animate correctly, we will collapse the UVW info. To do so, verify that the 2 UVW Mapping Modifiers are below the MeshSmooth modifier, and then right-click on the upper one and choose Collapse To, thus their info will be collapsed in the editable mesh, but will still remain. Activate the Animation mode then select the lower state of the stack Editable mesh and go to sub-object level Vertex.
Goto Frame 100, check that Animate is on and then select the vertices of the 'head' of the explosion, and upper them a bit. Then select then vertices of the bottom of the explosion, but not the one at the base of the central cylinder, and scale them on X and Y axis, this will make the smoke spread. Then play, if the speed seems correct go on, if not, adjust...
Now that the mesh is animated, we will have to animate the fire materials. Since the cellular maps are all set to World XYZ, they won't move as the mesh is deformed, so we have to animate it separately. Go to frame 100 again, and check you're in Animate mode. Now go in your Material editor, and go into each cellular map you have (for each fire/smoke materials you have) and put a value of -30 in Offset Z: , once it's done for each map, make an render of your 100 frames, and look if the fire goes up as fast as the mesh, for nice effect it have to go at least as fast. If not, lower the value in each map again (still in Anim mode) until you've something ok.

Make a render, the Animation is done.
The landscape and surroundings around the explosion are mainly up to you, what i can recommend is a worm eye view and a wide fov for your camera, so the explosion looks bigger. The addition of particles is good, but wide smoke particles tend to 'eat' image info and mess up with effects.
Effects are very important for objects like explosion, a glow is very handful to make something look luminous. The effects i chose for this tutorial are :
glow, wide and red, only for the head of the explosion -
glow, sharp and almost white, only for unclamped colors -
blur radial 1% -
blur uniform 0.7 % -
Check the impact of the effects instead of nothing :

That's it ! The tutorial is over, i hope you got something nice in the end and learned a few things...
Here is a video of what i got in the end. It's DivX 5.02