Realistic Grass Tutorial    

In this tutorial we will learn how to create a realistic grass material using the displacement and various other material properties. The end result will be a 3dimensional grass rather than a 2d bitmap.

Here is what the end result will look like....


 
     

The first thing you should do is obtain a birdseye view (non-persectival) of grass.

Example

 
     

Set up a scene. Create a simple plane and a daylight system found under Create>systems>daylight systems.

Your scene should look somethign like this....

 
     

Create a Mental Ray material. For the surface map use a

DGS Material (3dsmax)

Click on the diffuse mapping box (the grey box next to the color swatch) and then select bitmap and use your image of grass. This will give the surface the color.

 
     

The next step is creating a displacement map so the surface becomes blades of grass, rather than a flat surface.

Go back to your parent for the material and for your displacement map, apply a Height Map Displacement (3dsmax).

 
     

Within the Height displacement Map we are now able to specify the range of our displacement, or the height and depth of our grass blades.

Set the minimum to 0'0"

Set the maximum to 0'7"

We now need to specify a Height Map. Meanning map that will specify which areas are displaced and which are not based on its color value.

We will use a cellular map.

If you render you can see these bumps appear for our material.

 
     


We need to adjust our cellular map properties in order to get our displacement to appear like more of blades than bumps.

Adjusting the size and spread will give us varying appearances.

to get a blade like appearance turn your

size= .5

spread = .5

You will notice this will take a good deal of time to render because our geometry has become much more complex from our displacement mapping.

 
     

We also need to control our displacement mapping in our rendering controls. If you open up your rendering options and go to

Renderer>

Shadows and Displacement

There is a limit to which the renderer will compute in terms of displacement height. Here you can change the value. For example If we wanted to change the heigh to 2'0" we have to change it here and in our material.

 

     

The next thing we want to do is apply a bump map to our material to create a slight color variation in the grass.

For your bump map apply a bump (3ds max material)

Now apply a noise map.

You can see the patches of light and dark areas that now occur, making a much more realistic map.