Let's start off by creating the scene where we will make our grass.

• Create a grid (Toolbar > Ctrl + Grid).
• Scale up the grid to 5 and rename it 'ground'.

• Go to mat and tab-create an Arnold Material Builder.
• Rename it 'ground'.
• Drag the material onto the grid to assign it.
• Enter the Arnold Material Builder and create a standard_surface shader.
• Connect the shader output to the Surface input of the OUT_material node.
• Set the base_color to a suitable soil earth brown color.
• Attach the vopnet to the ground grid.

• Go back to obj level and tab create an Arnold Light.

Under the Light tab:

• Set the exposure to 3.
• Set the samples to 3.
• Change the Light Type to Skydome.
• Change the Color Type to Shader.

• Click the GoTo arrow next to the Color Shader parameter path box. Tab-create a physical_sky and attach the output to the Color input of the OUT_light.
• Create an Environment Output, and attach the physical_sky1 to the background of the OUT_environment.

• Now go to Outputs and tab-create an Arnold ROP.
• Attach a shader to the Environment slot in the ROP by clicking on the operator chooser and clicking obj > arnold_light1 > shopnet and select arnold_vopnet.

• Create a camera (rename it to 'RenderCam', and render the scene in the Render View.

Now that we have some ground and lights, we can move onto creating the grass.