diff --git a/Readme.md b/Readme.md
index 4752387..9c911b8 100644
--- a/Readme.md
+++ b/Readme.md
@@ -1,10 +1,28 @@
-# compilation
-git clone https://github.com/ssloy/tinyraytracer.git  
-cd tinyraytracer  
+# Homework assignment
+
+Add environment maps:
+![](https://raw.githubusercontent.com/ssloy/tinyraytracer/homework_assignment/out-envmap.jpg)
+
+... and triangulated meshes:
+![](https://raw.githubusercontent.com/ssloy/tinyraytracer/homework_assignment/out-envmap-duck.jpg)
+
+All the boring code (image/obj files serializer etc) is already there; to obtain the above image it suffices to add 10-20 lines of code.
+
+
+## compilation
+```sh
+git clone --recurse-submodules https://github.com/ssloy/tinyraytracer.git
+cd tinyraytracer
 git checkout homework_assignment
 git submodule update
-mkdir build  
-cd build  
+mkdir build
+cd build
 cmake ..  
-make  
+make
+```
+You can open the project in Gitpod, a free online dev evironment for GitHub:
 
+[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/ssloy/tinyraytracer/tree/homework_assignment)
+
+On open, the editor will compile & run the program as well as open the resulting image in the editor's preview.
+Just change the code in the editor and rerun the script (use the terminal's history) to see updated images.