Here i am writing my first tutorial for making sunset clouds in 3ds max.Which explains how i created clouds in final image of Lighthouse for "Finding Shore" compitition.It's a step by step tutorial.so please take a patience to read it.
1.Create a 100000"x100000" plane at origin.and create "Target camera" in
viewport.Position the "camera01" to (0,0,68") and "Camera01 Target" to (0,100,80).
2.Create a Geosphere(at origin) in Top Viewport with 10000" Radius and check On "Hemisphere" and "Base to Pivot" Option.Move it down a little below the plane. Apply "Normal" and "UVW map" Modifiers to geosphere.and Align the UVW map modifier to "Y" axis.Scale it down to 30% in Left viewport.Change the "Lenght" parameter to 10000 in "UVW map" modifier.
3.Create a new 100% self illuminated material.Load a "Gradient" map to diffuse
Slot.Change the Color#1 RGB value to 0,21,75, Color#2 to 131,124,175 and color#3 to 112,63,0. Set the "Color 2 position" to 0.4. and Assign this material to Geopshere in the scene.
4.Now Create another Geosphere(at origin) with Settings shown in the image.
Rename it to "Clouds".Apply "Normal" and "UVW map" Modifier.Scale it down to 30%.and move it down below the the ground plane.
5.Now Creat a new "standard" material.Label it "Clouds".check on "Self lumination" Load a "Mask" Map in Opacity slot.Now in "Mask" map, load the "Gradient" Map in the "Mask" slot.Change the "W" angle to 90.In Gradient Parameters, change Color#2 to white.and set its position to 0.7 and Gradient Type to Radial.Check on "Enable Color Map" and amend the curve as shown in the image.
6.Go back to "Mask map" and load a "Noise" Map in map slot.Change the "Blur" to 0.2 and
In Noise Parameters,
Noise Type : Fractal,
Noise Thresold : High = 0.8, Low = 0.35, Levels : 10
Size : 0.1
and In the output panel,Check on the "Enable Color Map" and amend the curve as shown in the image.
7. Copy this "Noise" map and "Paste(Copy)" it to diffuse slot of the same
material.Change Color#1 RGB value to 182,126,91 and Color#2 RGB Value to 163,92,50.Also Change the "Output amount" to 7 and curve as shown in the image.Copy and paste(instance) this map in Self illumination slot of the same material.
8.Clone(Copy) this "Clouds"(geosphere) object and rename it to "Clouds Shadow".In material editor, Copy "Clouds" material in new slot. and rename it "Clouds shadow".Assign this material to new object in the scene.Go into diffuse slot of "Clouds Shadow" material.change the Noise maps color#1 and color#2 to 78,74,109 and 23,18,114 respectivly.change the "output amount" to 3.
9.We will Scale down and offset the position of this new object to generate the shadow for clouds.Now in the viewport, Right click on http://www.jhjariwala.com/scale.jpg button to bring out the "Scale Transform" dialogue box and change "Offset World" Value to 99.(Assuming sunlight is coming form left to camera),Offset the position of "Clouds Shadow" object.Change its X and Y postion coordinates to 50 and -20 respectivly.
you might also need to move it down to Z axis.Keep offsetting the sphere in all axis(approx. 10 units) until you get satisfied with shadow.
10. Render out the final image of clouds. http://www.vizdepot.com/forums/images/smilies/smile.gif
Well you can take this further away and can render out various clouds with various settings.you also can use photoshop to composite various rendered cloud images.Changing Noise map's(in Opacity slot) Size,Offsetting its position, thresold as well as changing curves can give u various shape of clouds.You can also use other maps like "cellular","smoke" etc maps and can generate various clouds shapes.but personally i found noise map more easy to control the clouds shape.you can also make "Sky/Clouds" hdri for your scene.(By rendering out 32-bit panorama image in mentalray.)
Here is the final scene of the tutorial.
link : http://www.jhjariwala.com/Jigu_Final_Clouds.max (http://www.jhjariwala.com/Jigu_Final_Clouds.max)
If u have any questions ,feel free to ask me here.:)
I hope this tutorial will help you.