Created 15 september 2000
Version 1.0

Placing the firestorm effect in the scene

Begin by creating a spherical atmospheric gizmo (create panel-helpers-atmospheric aparatus) at coordinates (0, 0, 0). Note: the boxgizmo doesn’t work yet with firestorm. Make the radius 40. Offcourse this isnt really important in future work but for the clarity of this tutorial its important that we both start from the same point. Now go to rendering in the menu bar and choose environment.  Change the background color to a light blue tone (the color of a cloudless sky). In the atmosphere rollout press “add” and choose the “firestorm” effect from the list. If it isnt availabe to choose from you havent installed the plugin properly. Note: firestorm cannot be added by selecting the gizmo, going to the modifier tab and then scrolling down to the atmospheres rollout. However; once it is added it will be shown in that list and can be selected and edited. After you have added the firestorm effect all parameters will be availabe to edit and tweak. Don’t be overwhelmed by the amount of parameters. There is no need for that. First thing we have to do now is to tell firestorm what gizmo it should use. At the top of the general parameters rollout you can pick the gizmo we just made. Press “pick” and click on the gizmo in one of the viewports. Note that you can have several gizmo’s assigned to the same effect to make multiple clouds.Now that we have added the firestorm effect and assigned it to a gizmo we can render the scene and see what happens. Make sure your  perspective view is active. Firestorm wont render from any orthographic views.

 

 

Changing the color of the cloud

If all went well you should have a nice colored ball of smoke. Dark orange and more like an explosion then a cloud. Lets start by changing the color. You can find the settings for this in the “base color” frame. Since clouds are white we change both colors (inner and outer) to pure white. You can try a very light grey aswell but any non white tints tend to give the cloud a smokey appearance very quickly. Now render again. Much better don’t you agree? Next we will explore the “primary sampling” frame a bit before we start changing the real appearance of the cloud. Most important are opacity, samples and density. The difference to opacity and density can be described as follows. Density controls more how thick the cloud feels. It has the most effect on the places where the clouds allready is quite solid. Opacity works differently in that it controls more the surface of the cloud. Try setting it to a higher value to see what I mean. You can make very solid smoke by playing with this setting (good for rocket trails or vulcano smoke). The “samples” parameter controls how much detail the renderer should put into the cloud. Most of the time this value can be decreased quite a bit before you start noticing a loss of detail. Very important parameter to optimize rendertime. Note: when experimenting with different types of noise and values its wise to keep the sample value quite high. Otherwise the chance exists that the renderer wont put enough detail into the cloud to show you what has changed thereby giving you the illusion that changing the parameters didn’t have any effect. To show how much the default sample value can be decreased in our case change it from 15 to 8 and see if you can find any difference with the previous renderer. Hardly don’t you agree? The difference in rendering time on my pc was from 12 seconds to 8. Not much in a small scene but a hellofalot when you have a full sky of clouds.

 

Changing basic appearance (puffiness) of the cloud

Next up is the “noise properties” framework. This is a very important place to create the look you want. You can compare the noise types to the noise procedural map like you know it from the material editor. Its essentially a 3d pattern running through space. Where its light the cloud appears, where its black there is no cloud. This is what gave our cloud the puffy look in the first place. Try setting the “noise amount” to 0 to see what happens. Boring eh? Without any noise the cloud just fills the gizmo. Change it back to its original value (1). Now experiment with some of the other noise types. Notice that all of them allow you to enter a value for the “level”. Increasing the level increases the detail in the noise. Note: to see some of the more subtle differences when changing noise values and types increase the sample and opacity value. It will look ugly but will also give you a very clear view on the different noise types and what each parameter does. Experimenting is the word here. If you are having trouble with some of the parameters and what they do go and play a bit with the normal noise material in the material editor. After you have experimented to your harts content with all the parameters you can change them back to their original values (cause they were fine in the first place) or keep your own.

 

 

Changing and controlling the shape of he cloud

To show what the “lock to world” option does we will first change the shape of the gizmo to represent the shape of a cloud better. Select “non uniform scale” from the toolbar and scale the gizmo in the top viewport along the x axis 400% Ignore the warning you get. Now zoom out in the perspective view so you can see the entire cloud again. Render the scene. As you can see something strange happened. The cloud got stretched along the x-axis! Offcourse this is not like a real cloud. This happens because of a very strange approach atmospherics take to noise in 3dsmax. Once you create a gizmo the noise is created inside the gizmo and “locked” to it. So if you scale the gizmo up you will also scale up the cloud. This also means that if you would clone this gizmo and assign the same firestorm effect to it you would have two perfectly identical clouds! Very bad and not what we want at all. If we would clone this gizmo and make it bigger we want a cloud that looks different, bigger then the original but with the same detail. This is what the “lock to world” option does. Instead of locking the noise to the gizmo the noise now exists in the world as a never ending pattern in all directions! Turn it on and render to see what I mean. Much better don’t you agree?

 

Before we are going to add a lightsource to the scene and  make the cloud cast shadows onto itself we first take a look at the “shaping functions” frame. As you know we use the gizmo to define the basic shape and place of the firestorm effect in the scene. The parameters you find here are to give a little extra control on the influence the gizmo has on the effect. “Regularity” controls how much the cloud should conform to the shape of the gizmo. Change its value to 1 to see what I mean. Render. Now change it to 0 to see the other extreme. Render again. As you can see this is a very important value to control the shape of the cloud. Change it back to 0.2 The “clamp” variables allow you to place some spacing between the effect and the “shell” of the gizmo. Change the “height clamp” value to 0.7 and render to see what happens. To remove the cleaniness of the effect you can give a bit of tolerance to the clamp value by inserting a small number in the “+/-“ box. Enter 0.2 in this box behing the “height clamp” value. Render again and notice the difference. Change the variables back to their original values or keep the new ones, whatever you like best.

 

 

Adding a light and shadowcasting

Create a target direct light at (1000, 1000, -500). Place the target at (–100, 0, -200). Note: you can place objects at specific coordinates by selecting them, clicking one time on the move icon in the toolbar and then rightclicking the same icon again. A window will pop up where you can enter these exact coordinates. Next go in the modifier tab and turn on “shadowcasting”. Now open the “directional parameters” rollout. Change the “hotspot” so that the beam from the light encloses the cloud in its entirety. (value about 300). Now check the option “overshoot”. You are done with the light.

 

We will approach the setup of firestorm in a different way this time. Select the atmospheric gizmo. Select the modifier tab. Scroll down untill you find the “atmospheres” rollout. Click firestorm from the list. Now click on “setup” to open the environment effects window. We are back in the firestorm setup screen. Open the “firestorm: illumination” rollout. Here you can choose what lights should influence the cloud. Click one time on the “pic” button and then click on the light we just created in any of the viewports. In the frame “shader control” we can turn shading on and off. Choose “constant” as shader. Leave the other settings as they are. In the “extended characteristics” choose a very light (and I do mean very light) blue as the ambient color. Note that the brightness of this color does –not- influence the ambient light level. This purely controls the ambient tinting of the clouds. (or at least thats what it appears to do). We skip the “light scattering” frame. Appearantly this function was used to help create the silverlined clouds in the southpark movie. In the “shadow properties” frame turn shadow casting off. In this scene its is not important and only slows down rendering. In the “self shadowing” frame we are finally able to enable the effect we want. Check “active”. Now render the scene. Not really perfect eh? This is why I tried to explain all the important functions to you. To get the result you want you should play a bit with the relevant parameters. I achieved the results I wanted after about 5 minutes of playing around.

 

Here are my last changes that lead to the final result:

 

“Firestorm: illumination” rollout

“Self shadowing frame”

“Density” changed from 5 to 3

 

“Firestorm: general parameters” rollout

“Primary sampling” frame

“Samples” changed from 8 to 15 (the default)

 

“Noise properties frame"

"High" changed from 1 to 0.5

 

“Shaping functions” frame

“Regularity” changed from 0.2 to 0.3

“Height clamp” changed from 0.7 to 1.0 (the default | tolerance set to 0 aswell)

“Width clamp” changed from 1.0 to 0.8

 

As a last tweak I also changed the ambient level from 1 to 1.4. Clouds are well lit and receive huge amounts of bounced light from clouds around them and from the ground. A higher ambient level helps to simulate this effect.

 

 

Credits:

Thanx to all the other people who took the time to write a tutorial on something about max. Without you guys i would be nowhere. Here is my little contribution to the online community.

 

I also want to thank the nice people at Maxforums for being such a great help and for being the nice people that you are. Thnx guys! Special thanx go out to skyraider for nagging me with his combustions clouds so i started experimenting with this great plugin!

 

And last but not least Blur Studios. For their awesome support to the maxcommunity by releasing very needed plugins and utilities for free. Thankyou guys; i hope this tutorial is usefull to many.