How to append component of one volume to another in custom application

Development
1

Hi Experts,
I have 2 datasets. One with 3 components (RGB) and the other as 1 component (A). I want to combine these two to form a single dataset of 4 components (RGBA). I implemented this using a programmable filter in ParaView GUI using numpy and stacking them. But I want to do it in a custom application. I cannot find an efficient solution to implement in custom application. How should I approach this?
Thanks Alot

2

Write it in a C++ VTK filter and add it as a plugin in your custom application.

3

Hi, thanks for the suggestion.
I have created a custom plugin for the vtkImageAppendComponents filter.
I have structured the project as followed:

src/
├── CMakeLists.txt
├── mainWindow.cxx
├── mainWindow.h
├── mainWindow.ui
└── ImageAppendComponents/
    ├── CMakeLists.txt
    └── Plugin/
        ├── CMakeLists.txt
        ├── ImageAppendComponents.xml
        └── paraview.plugin

paraview.plugin:

NAME
    ImageAppendComponents
DESCRIPTION
    expose vtkImageAppendComponents
REQUIRES_MODULES
    VTK::ImagingCore

This is how the XML file looks like:

<ServerManagerConfiguration>
	<ProxyGroup name="filters">
		<SourceProxy name="ImageAppendComponents" class="vtkImageAppendComponents" label="ImageAppendComponents">
			<Documentation
				long_help = ""
				short_help = ""
			</Documentation>

			<InputProperty
				name="Source"
				port_index="0"
				command="SetInputConnection">
				<ProxyGroupDomain name="groups">
					<Group name="sources"/>
					<Group name="filters"/>
				</ProxyGroupDomain>
				<DataTypeDomain name="input_type">
					<DataType value="vtkDataObject"/>
				</DataTypeDomain>
				<Documentation>
					Set the source data set.
				</Documentation>
			</InputProperty>

			<InputProperty
				name="Target"
				port_index="1"
				command="SetInputConnection">
				<ProxyGroupDomain name="groups">
					<Group name="sources"/>
					<Group name="filters"/>
				</ProxyGroupDomain>
				<DataTypeDomain name="input_type">
					<DataType value="vtkDataObject"/>
				</DataTypeDomain>
				<Documentation>
					Set the target data set.
				</Documentation>
			</InputProperty>

		</SourceProxy>
	</ProxyGroup>
</ServerManagerConfiguration>

Plugin/CMakeLists.txt:

paraview_add_plugin(ImageAppendComponents
        REQUIRED_ON_CLIENT
        REQUIRED_ON_SERVER
        VERSION "1.0"
        SERVER_MANAGER_XML ImageAppendComponents.xml)

ImageAppendComponents/CMakeLists.txt:

cmake_minimum_required(VERSION 3.8)
project(ImageAppendComponents)

include(GNUInstallDirs)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_BINDIR}")
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
set(BUILD_SHARED_LIBS ON)

find_package(ParaView REQUIRED)

set("_paraview_plugin_default_${PROJECT_NAME}" ON)
paraview_plugin_scan(
        PLUGIN_FILES "Plugin/paraview.plugin"
        PROVIDES_PLUGINS plugins
        ENABLE_BY_DEFAULT ON)

paraview_plugin_build(
  PLUGINS ${plugins})

Top Level CMake:

cmake_minimum_required(VERSION 3.8)
project(CustomPV)

set(ParaView_DIR /home/usr/Downloads/Paraview/paraview_build)
find_package(ParaView REQUIRED)

include(GNUInstallDirs)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_BINDIR}")
set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")
set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LIBDIR}")

find_package("Qt${PARAVIEW_QT_MAJOR_VERSION}" REQUIRED COMPONENTS Widgets)
find_package(VTK)
find_package(ParaView REQUIRED COMPONENTS VTKExtensionsFiltersGeneral RemotingViews)

set(CMAKE_AUTOMOC 1)
set(CMAKE_AUTOUIC 1)

set(SOURCES
  mainWindow.h
  mainWindow.cxx
  mainWindow.ui
)

add_executable(CustomPV main.cxx ${SOURCES})
target_link_libraries(CustomPV
  PRIVATE
    ParaView::pqApplicationComponents
    ${VTK_LIBRARIES} ${ParaView_Libraries}
    ParaView::RemotingSettings
    ParaView::RemotingViews
    ParaView::VTKExtensionsFiltersGeneral
    "Qt${PARAVIEW_QT_MAJOR_VERSION}::Widgets")

# Set include directories
target_include_directories(CustomPV PRIVATE ${ParaView_INCLUDE_DIRS})

add_subdirectory(ImageAppendComponents)

When I build the project, I am getting the following error:

The ImageAppendComponents's CMakeLists.txt may not add the
  ImageAppendComponents plugin.
Call Stack (most recent call first):
  ImageAppendComponents/Plugin/CMakeLists.txt:1 (paraview_add_plugin)
4

your VTK module and your plugin cannot share the same name.