images and phase 3 updates

Tutorial/Phase3.md

 # Perception Tutorial
 ## Phase 3: Cloud
 
-In this phase of the tutorial, we will learn how to run our Scene on Unity Simulation. This will allow us to generate a much larger dataset than what is typically plausible on a workstation computer. To 
+In this phase of the tutorial, we will learn how to run our Scene on _**Unity Simulation (USim)**_. This will allow us to generate a much larger dataset than what is typically plausible on a workstation computer.
-* **Action** Click on the _**Cloud**_ button at the top-right corner of Unity Editor.
+* **Action** Click on the _**Cloud**_ button at the top-right corner of Unity Editor to open the _**Services**_ tab. 
+
+<p align="center">
+<img src="Images/cloud_icon.png" width="400"/>
+</p>
+
+If you have not logged in yet, the _**Services**_ tab will display a message noting that you are offline:
+
+<p align="center">
+<img src="Images/signin.png" width="400"/>
+</p>
+
+* **Action**: Click _**Sign in...**_ and follow the steps within the window that opens to sign in or create an account.
+* **Action**: Sign up for a free trial of Unity Simulation [here](https://unity.com/products/unity-simulation).
+
+Unity Simulation is a cloud-based service that makes it possible for you run thousands of instances of Unity builds in order to generate massive amounts of data. 
+
+The USim service is billed on a per-usage basis, and the free trial offers up to $100 of free credit per month. In order to access the free trial, you will need to provide credit card information. **This information will be used to charge your account if you exceed the $100 monthly credit.** A list of hourly and daily rates for various computational resources is available in the page where you first register for USim.
+
+Once you have registered for a free trial, you will be taken to your USim dashboard, where you will be able to observe your usage and billing invoices.
+
+It is now time connect your local Unity project to a cloud project and your simulation on USim.
+
+* **Action**: Return to Unity Editor. In the _**Services**_ tab click _**Select Organization**_ and choose the only available option (which typically has the same name as your Unity username).
+
+If you have used Unity before, you might have set-up multiple organizations for your account. In that case, choose whichever you would like to associate with this project.
+
+<p align="center">
+<img src="Images/create_proj.png" width="400"/>
+</p>
+
+* **Action**: Click _**Create**_ to create a new cloud project and connect your local project to it.
+
+The process of running a project on Unity Simulation involves building it for Linux and then uploading this build, along with a set of parameters, to Unity Simulation. The Perception package simplifies this process by including a dedicated _**Run in USim**_ window that accepts a small number of required parameters and handles everything else automatically.
+
+In order to make sure our builds are compatible with USim, we need to set our project's scripting backend to _**Mono**_ rather than _**IL2CPP**_. The latter is the default option for projects created with newer versions of Unity.
+
+* **Action**: From the top menu bar, select _**Edit -> Project Settings**_.
+* **Action**: In the window that opens, navigate to the _**Player**_ tab, find the _**Scripting Backend**_ settings and change it to _**Mono**_:
+
+<p align="center">
+<img src="Images/mono.png"/>
+</p>
+
+sudo spctl --master-disable
+
+
+need to put in credit card