ml-agents/unity-environment/Assets/ML-Agents/Examples/PushBlock/Scripts/PushBlockAcademy.cs

//Every scene needs an academy script. 
//Create an empty gameObject and attach this script.
//The brain needs to be a child of the Academy gameObject.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PushBlockAcademy : Academy
{

    /// <summary>
    /// The "walking speed" of the agents in the scene. 
    /// </summary>
	public float agentRunSpeed;

    /// <summary>
    /// The agent rotation speed.
    /// Every agent will use this setting.
    /// </summary>
	public float agentRotationSpeed;

    /// <summary>
    /// The spawn area margin multiplier.
    /// ex: .9 means 90% of spawn area will be used. 
    /// .1 margin will be left (so players don't spawn off of the edge). 
    /// The higher this value, the longer training time required.
    /// </summary>
	public float spawnAreaMarginMultiplier;

    /// <summary>
    /// When a goal is scored the ground will switch to this 
    /// material for a few seconds.
    /// </summary>
    public Material goalScoredMaterial;

    /// <summary>
    /// When an agent fails, the ground will turn this material for a few seconds.
    /// </summary>
    public Material failMaterial;

    /// <summary>
    /// The gravity multiplier.
    /// Use ~3 to make things less floaty
    /// </summary>
	public float gravityMultiplier;

    void State()
    {
        Physics.gravity *= gravityMultiplier;

    }
}