Fix openVDB build on Ubuntu 24.04 by replacing obsolete Half library with Imath

Author: bartoszkosiorek

CMakeLists.txt

@@ -10,7 +10,7 @@
 #
 #******************************************************************************
 
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 3.5)
 project (MantaFlow)
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/tools/cmake/")
@@ -122,10 +122,6 @@ else()
   set(PYTHON_VER_ID ${PYTHON_VERSION})
 endif()
 
-if(OPENVDB AND NOT TBB)
-	message(FATAL_ERROR "Cannot activate OPENVDB without TBB")
-endif()
-
 MESSAGE(STATUS "")
 MESSAGE(STATUS "Options - "
 	" -DDEBUG='${DEBUG}' "
@@ -387,7 +383,7 @@ if(OPENVDB)
 		else()
 			message("Warning - OpenVDB not found, trying default paths") 
 			# might be in path...
-			list(APPEND F_LIBS Half openvdb tbb)
+			list(APPEND F_LIBS Imath openvdb tbb)
 		endif()
 	endif()
 
@@ -399,7 +395,7 @@ if(OPENVDB)
 			list(APPEND INCLUDE_PATHS ${HOUDINI_INCLUDE_DIRS})
 			list(APPEND INCLUDE_PATHS ${HOUDINI_INCLUDE_DIRS}/OpenEXR)
 			list(APPEND F_LIB_PATHS ${HOUDINI_LIBRARY_DIRS})
-			list(APPEND F_LIBS "Half.lib")
+			list(APPEND F_LIBS "Imath.lib")
 		endif()
 	else()
 		# for open exr - should be in the default path, add includes if necessary

README.md

@@ -1,7 +1,7 @@
 # Mantaflow #
 
 Mantaflow is an open-source framework targeted at fluid simulation research in Computer Graphics.
-Its parallelized C++ solver core, python scene definition interface and plugin system allow for quickly prototyping and testing new algorithms. 
+Its parallelized C++ solver core, python scene definition interface and plugin system allow for quickly prototyping and testing new algorithms.
 
 In addition, it provides a toolbox of examples for deep learning experiments with fluids. E.g., it contains examples
 how to build convolutional neural network setups in conjunction with the [tensorflow framework](https://www.tensorflow.org).
@@ -17,7 +17,7 @@ This installation guide focusses on Ubuntu 24.04 as a distribution. The process
 
 First, install a few pre-requisites:
 
-    sudo apt install pt-get install cmake g++ git python3-dev qt5-qmake libqt5opengl5-dev libopenvdb-dev
+    sudo apt install pt-get install cmake g++ git python3-dev qt5-qmake libqt5opengl5-dev libtbb-dev libopenvdb-dev
 
 If you want to enable CUDA support, additionally get the latest toolkit from nVidia, and install the appropriate developer driver (be careful though, these driver tend to wreck X11 - get some installation instructions from the web if this is the first time you install CUDA on Linux)
 
@@ -29,8 +29,12 @@ To build the project using CMake, set up a build directory and choose the build
 
     mkdir mantaflow/build
     cd mantaflow/build
-    cmake .. -DGUI=ON -DOPENMP=ON
-    make -j4
+    cmake .. -DGUI=ON -DOPENVDB=ON
+    make -j8
+
+To build Mantaflow with OpenVDB support with Threading Building Blocks (TBB), you need to disable GUI. There is an issue with duplicated symbols between Qt and Threading Building Blocks (TBB):
+
+    cmake .. -DTBB=ON -DOPENVDB=ON
 
 That's it! You can now test mantaflow using an example scene