Poly modeling methods

(1) Vertex displacement with Soft Selection

This is a very easy and simple method. However it is very difficult to make the terrain realistic using this method. The quality of the terrain is directly depending on the 3d artist’s performance.
Several poly modeling methods can be used to make the terrain. The first step of all these methods is to create a plane with higher amount of Length and Width Segments. (eg. 50X50, 100X100 or even higher). Convert the plain to Editable Poly object. Go to sub-object levels such as polygon, vertex and edge and displace them (especially through the Z axis) by using Soft Selection option. The main tools which will be used to displace will be Select and Move toggle and the few parameters listed under Soft Selection rollout. However, Select and Rotate toggle and Select and Scale toggle may also be used according to your need.
The best procedure to follow when using this method is to start with higher value of Falloff (under Soft Selection rollout) and then go to smaller and smaller Falloff values step-by-step. This will help you to make the basic shape of the terrain and add more and more details later.

However it is mode time consuming task to add more detail to the terrain.

(2) Vertex displacement by Paint Deformation

This method is little bit easier to use and bit faster than the early method. Create a plane with higher number of segments as early. Convert the Plane into Editable Poly. Turn on the Push/Pull button in the Paint Deformation rollout, and draw the terrain on the plane as you like. In this method also you can start with basic shape of the terrain using bigger Brush Sizes, and then go to further details by reducing the brush size little by little.
Keep in mind not to click and drag the brush on the plane. It will make your terrain unrealistic. Add detail by clicking at every point you want.

This method is also take some time when go in to further details.

Using Displace modifier

This is very simple, quick and more realistic method. Create a square plane with higher amount of segments (we can increase it later). Open Material Editor (press M), Click the small button in front of the diffuse colour in the Blinn Basic Parameters rollout and select Smoke from Material/Map Browser.
Select the plane and add Displace modifier to it. Click the None button under Map: in the Parameters rollout and select early created Smoke material from the Material/Map Browser (Select “Mtl Editor” from Browse From group on the left side of the Material/Map Browser). You may not see any difference. Don’t worry; increase the Strength value in the Parameters rollout until the mountains are well build.
Go to Smoke material you have created, and adjust its parameters. You can get different shapes of terrain in a flash. Surely it will be more realistic than what you have created early. There is another advantage when using this method. That is you can be back to plane you created and poly density of the plane can be change as you want.

But there is a one disadvantage. Were you able to find it? It is you can’t model the terrain in a way that you want using this method. But you can use several methods to overcome this problem. One such way is to use the Bitmap option instead of Map option we have selected early. If you are using this method you can make the displacement map using Photoshop as a grayscale image. In this case you can use Photoshop and 3d max simultaneously. 3d max automatically updates the terrain when you edit and save the image using Photoshop.

Better ways of modeling terrain

By understanding advantages and disadvantages of each and every method which can be used to model terrain, I have come out with my own novel method with all the positive points.
Create a plane with a desired size and increase the number of side segments in to a moderate value (don’t worry you can increase the number of segments as you need later). Apply a Displace modifier to it. Create the basic shape of the terrain using Photoshop (don’t add details to it).

Apply the created bitmap as the Displacement map. Increase the Strength of the Displace modifier until it looks like what you wanted. Sometimes you may not get a smooth surface, don’t worry about that.

Switch off the Displace modifier and apply another Displace modifier (on top of the existing modifier). Create a smoke material and apply it as the Displace map to new modifier. Increase the Strength of the modifier as you like, and then adjust the parameters of Smoke until you get a good looking rough surface. (It is not possible to tell the values, better to use trial and error procedure. However keep the # Iterations as 20)

Then turn on the Displace modifier you have turned off earlier. You will get a nice looking terrain with the basic shape you wanted. If the basic shape of your terrain is changed much from the second Displace modifier, decrease the strength of the second Displace modifier.