update docker instructions to check EGL on host (#48)

INSTRUCTION.md

@@ -27,18 +27,23 @@ House3D runs on Linux/MacOS with or without Nvidia GPUs.
 
 ### Use Dockerfile:
 If you're on a Linux with Nvidia GPUs,
-we recommend trying the [Dockerfile](Dockerfile) to run House3D,
-so you don't have to worry about the build process. To use the docker file, you need to have
-`nvidia-docker`, then run:
+we recommend using the [Dockerfile](Dockerfile) to run House3D,
+so you don't have to worry about the build process.
+To use the docker file, you need to install `nvidia-docker`, then run:
 
 ```bash
+# If this command cannot find `libEGL_nvidia`, your driver installation is incomplete.
+nvidia-container-cli list -l | grep libEGL_nvidia 
+# Build the docker
 docker build -t house3d:v0 .
-xhost local:root     # run this command only if you need to use GUI within docker
+# Run this command only if you need to use GUI within docker
+xhost local:root
+# Start the container
 nvidia-docker run -it --name house3d --net=host \
     --env="DISPLAY" --volume="/tmp/.X11-unix:/tmp/.X11-unix:rw" \
 		house3d:v0
 # the "env" and "volume" options are only useful if you need to use GUI within docker
-# Now you should be inside the docker and House3D is ready to use. You can:
+# Now you should be inside the container and House3D is ready to use. You can:
 
 cd /House3D/renderer && ./objview-offline.bin $TEST_HOUSE   # offline rendering, produce an image file
 cd /House3D/tests && python3 test-rendering.py $TEST_HOUSE --interactive  # interactive rendering with GUI

renderer/DEPENDENCIES.md

@@ -9,6 +9,9 @@ In a nutshell, you need the following libraries:
 + libglvnd (needed on certain systems)
 
 The way to install these dependencies is different on various platforms.
+For people not familiar enough with Linux, they are not easy to install manually.
+That's why we recommend using docker to avoid the build process.
+
 These are some platforms we've tested on:
 
 ### Ubuntu 16.04
@@ -49,7 +52,7 @@ yum install libX11-devel glfw-devel glm-devel mesa-libGL-devel mesa-libEGL-devel
 Install libglvnd the same way as above.
 
 ### Ubuntu 14.04 with Nvidia GPU
-```
+```bash
 apt install libx11-dev libegl1-mesa-dev libpng-dev libjpeg-dev
 ```
 
@@ -76,13 +79,13 @@ Later, remember to compile the renderer with `INCLUDE_DIR=-I/path/to/INSTALL_DIR
 
 Install EGL headers (the headers in apt is too old):
 ```
-cd INSTALL_DIR
+cd SOME/INSTALL_DIR
 wget -P EGL https://www.khronos.org/registry/EGL/api/EGL/egl.h
 wget -P EGL https://www.khronos.org/registry/EGL/api/EGL/eglext.h
 wget -P EGL https://www.khronos.org/registry/EGL/api/EGL/eglplatform.h
 ```
 Later, remember to compile `INCLUDE_DIR=-I/path/to/INSTALL_DIR make`.
 
-If multiple `INCLUDE_DIR` need to be added, use `INCLUDE_DIR=-I/path/one -I/path/two`.
+If multiple `INCLUDE_DIR` need to be added, use `INCLUDE_DIR="-I/path/one -I/path/two"`.
 
 Install libglvnd the same way as above.