Updated README.md for OCCT/IfcOpenShell7

ssg3d · aothms · commit 85e3c6588f60 · 2021-12-31T13:46:13.000+01:00
After IfcOpenShell#1930 the 0.7 branch isn't compatible anymore with OCCT version < 7.2. That includes the liboce that's found in debian (derivatives), which is OCCT 6.9 or even less. Updated the Linux section of README.md to explain the dependency on OCCT and include instructions to build on Unix with OCCT (from the OS repository as well). Also included changes that became necessary when we moved to v0.7.0 from v0.6.0 (like recursive clone and cmake additions).
diff --git a/README.md b/README.md
@@ -35,7 +35,9 @@ Dependencies
 Building IfcOpenShell
 ---------------------
 
-**Note:** The path where the source code is cloned to can contain spaces but non-ASCII characters are very likely to cause problems with the build.
+Note 1: The path where the source code is cloned to can contain spaces but non-ASCII characters are very likely to cause problems with the build.
+
+Note 2: If you had not used `git clone --recursive https://github.com/IfcOpenShell/IfcOpenshell.git`, update the submodules by running `git submodule init & git submodule update`.
 
 ### Compiling on Windows
 The preferred way to fetch and build this project's dependencies is to use the build scripts
@@ -83,17 +85,26 @@ The following instructions are for Ubuntu, modify as required for other operatin
 can be experimented with and studied for pointers for other operating systems, but note that this script is not currently
 meant to be used for a typical IfcOpenShell workspace setup.
 
-Note: where `make -j` is written, add a number roughly equal to the amount of CPU cores + 1.
+Note 1: It is recommeded to use OCCT for IfcOpenShell. You could use OCE as well, but sometimes it may lag behind OCCT and 
+therefore not compile with the latest IfcOpenShell.
+
+Note 2: where `make -j` is written, add a number roughly equal to the amount of CPU cores + 1.
 
 **1)** Install most of the prerequisites and dependencies:
 
-    $ sudo apt-get install git cmake gcc g++ libboost-all-dev
+    $ sudo apt-get install git cmake gcc g++ libboost-all-dev libcgal-dev
+
+**2a)** Either use an OCCT package from your operating system's software repository
 
-**2a)** Either use an OCE package from your operating system's software repository
+    $ sudo apt-get install libocct-data-exchange-dev libocct-draw-dev libocct-foundation-dev libocct-modeling-algorithms-dev libocct-modeling-data-dev libocct-ocaf-dev libocct-visualization-dev
+
+**2b)** or, if OCCT is not available or the latest code is wanted, obtain and compile OCCT from https://dev.opencascade.org/release
+
+**2c)** or, if you'd like to try using OCE, use the package from your operating system's software repository
 
     $ sudo apt-get install liboce-foundation-dev liboce-modeling-dev liboce-ocaf-dev liboce-visualization-dev liboce-ocaf-lite-dev
 
-**2b)** or (if not available, or the latest code is wanted) compile OCE yourself (note that the build takes a long time):
+**2d)** or if OCE is not available, or the latest code is wanted, compile OCE yourself (note that the build takes a long time)
 
     $ sudo apt-get install libftgl-dev libtbb2 libtbb-dev libgl1-mesa-dev libfreetype6-dev
     $ git clone https://github.com/tpaviot/oce.git
@@ -103,8 +114,6 @@ Note: where `make -j` is written, add a number roughly equal to the amount of CP
     $ make -j
     $ sudo make install
 
-**2c)** or obtain and compile OCCT from https://dev.opencascade.org/release
-
 **3)** For building IfcConvert with COLLADA (.dae) support (on by default), OpenCOLLADA is needed:
 
     $ sudo apt-get install libpcre3-dev libxml2-dev
@@ -130,7 +139,13 @@ dependencies' paths. `OCC_INCLUDE_DIR` might be needed to set also. `OPENCOLLADA
     $ cmake ../cmake -DOCC_LIBRARY_DIR=/usr/lib/x86_64-linux-gnu/ \
           -DOPENCOLLADA_INCLUDE_DIR="/usr/local/include/opencollada" \
           -DOPENCOLLADA_LIBRARY_DIR="/usr/local/lib/opencollada"  \
-          -DPCRE_LIBRARY_DIR=/usr/lib/x86_64-linux-gnu/
+          -DPCRE_LIBRARY_DIR=/usr/lib/x86_64-linux-gnu/ \
+          -DCGAL_INCLUDE_DIR=/usr/include \
+          -DGMP_INCLUDE_DIR=/usr/include \
+          -DMPFR_INCLUDE_DIR=/usr/include \
+          -DGMP_LIBRARY_DIR=/usr/lib/x86_64-linux-gnu \
+          -DMPFR_LIBRARY_DIR=/usr/lib/x86_64-linux-gnu \
+          -DHDF5_SUPPORT=Off
     $ make -j
 
 If all worked out correctly you can now use IfcOpenShell. See the examples below.
