added readme file

README.md

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-# PotatoBenchmark
+# The Potato Benchmark Project
+
+Potato Benchmark is an benchmark project to make it easy to compare performance between LWRP and Built-in pipelines. It contains some baseline performance test scenes that specifically stress parts of the graphics pipeline such as test fill rate of built-in shaders, batching/driver cost and bandwidth. 
+
+The benchmark is still WIP. It builds for Android (GLES2, GLES3, Vulkan) and iOS (Metal) a set of test scenes in LWRP and Built-in. A main scene allows to select which pipeline to test. Each tests scene warms up for 2s. and measure frame times (average, median, min, max) in a period of 8s.
+
+# How to use it
+
+## Building to mobile
+
+In the Unity toolbar select `Tools` then select the target API to built.
+This will either generate an .APK file or an XCode project.
+
+## Building to other platforms
+
+There's no custom build script for other platforms other than mobile. You have to switch manually to the platform and build scenes. That's it. 
+
+## With Test Runner
+
+Go to `Window -> General -> Test Runner`. Then tests can run on either editor or deploy to target device.
+Then to see results go to `Window -> Analysis -> Performance Test Report`
+
+# Running Tests
+
+An main menu will display two buttons to select with Pipeline benchmark tests to run. Results will be outputted to console. 
+You can filter console output with `[Benchmark]`. F.ex on in Android use the following command line: `adb logcat -s Unity | grep [Benchmark]`.
+
+Note: If you are running in mobile, please remember to give 2min rest between each pipeline test.
+
+# Detail about current Tests
+
+
+## Fill rate tests
+Stress GPU fragment (ALU/Texture) by rendering a native device resolution set of fullscreen quads. Test is designed to achieve 2.5x overdraw which is acceptable rate for a mobile game.
+The purpose of the fill rate tests is to compare performance of single vs multiple passes strategies for each pipeline built-in shaders in different devices.
+ - Lit shader (Directional Light Only)
+ - Lit shader (1 Directional + 4 point lights per-pixel)
+
+## Draw Call (GPU)
+
+Stress GPU by issueing a considerable number of drawcalls that can be batched. 
+
+Tests have about 1k block building and one directional shadow casting light + PCF Filtering.
+The purpose of the realtime shadow test scene is to compare how each pipeline handles shadow culling, rendering and depth pre-pass.
+
+Test with and without cascades.
+ - Realtime Shadows
+ - Realtime Shadows Cascades
+
+## Draw call (CPU) 
+Test batching/cost of drawcall setup by stressing CPU with 2.7k simple drawcalls each with a different materials.
+The purpose of this tests scene is to compare the SetPass cost for each pipeline. 
+
+## Bandwidth
+Stress bandwidth cost.
+
+The purpose of this test is to figure out points of improvements in terms of bandwidth cost to have a very lean pipeline in term of LOAD/STORE. Currently we have a lot of room for improvement in terms of bandwidth when using MSAA.
+
+# Credits
+
+- Spawn Object script adapted from Arnaud's Batcher.