Providing values of adjacent voxel with vtkDiscreteMarchingCubes

The contribution to VTK presented in this article is an extension to vtk::vtkDiscreteMarchingCubes to also create vtk::vtkPointData scalars containing the value of the adjacent voxel. These can be used to remove regions of the marching-cubes 1 mesh depending on the local neighborhood. The extension is based on the code of vtkDiscreteMarchingCubes of VTK-6.3.0 and is available on GitLab https://gitlab.kitware.com/vtk/vtk/merge_requests/889 (and GitHub https://github.com/Kitware/VTK/pull/18).

Extracting Intersections of Coplanar Surfaces (Boolean-operation on touching meshes)

The contribution to VTK presented in this article is specialized on the extraction of contact surfaces (CS). This extraction can be regarded as the intersection Boolean-operation of only touching meshes. The vtkCoplanarSurfaceExtractor filter produces either polygonal or triangulated CSs by reconstructing the contact faces of co-planar triangles. Specified tolerances account for discrepancies in coplanarity of faces which might occur due to rounding effects. This article is accompanied with the source code, input data, parameters and output data that were used for validating the VTK-filter.

VTK Remote Rendering of 3D Laser Scanner Ply files for Android Mobile Devices

Three-dimensional laser scanner is a modern technology used to detect and capture the shape of complex objects. There are a lot of possible application fields for this technology: applications in the industrial sector (reverse engineering), in the medical field or in the cultural heritage field for virtual reconstruction of works of art. The main goal of this work is to make accessible the three-dimensional models obtained from laser scans on mobile devices (smartphones, tablets), exploiting a remote rendering application on high-performance workstations. This paper also shows how this can be done fairly easily using one of the most popular instruments in the field of scientific visualization, VTK.

Geodesic Computations on Surfaces

The computation of geodesic distances on a triangle mesh has many applications in geometry processing. The fast marching method provides an approximation of the true geodesic distance field. We provide VTK classes to compute geodesics on triangulated surface meshes. This includes classes for computing the geodesic distance field from a set of seeds and to compute the geodesic curve between source and destination point(s) by back-tracking along the gradient of the distance field. The fast marching toolkit (Peyre et. al.) is internally used. A variety of options are exposed to guide front propagation including the ability to specify propagation weights, constrain to a region, specify exclusion regions, and distance based termination criteria. Interpolators that plug into a contour widget, are provided to enable interactive tracing of paths on meshes.

Adding Refined Isosurface Rendering and Shadow Mapping to vtkGPUVolumeRayCastMapper

In the medical simulation world the use of isosurfaces is a common action, as the information from some sources, e.g. CTs, is very well defined, and the isosurface can be easily set. Additionally, in any simulator shadows are a necessary addition to increase the users immersion as well as its depth perception. Unfortunately, the Visualization Toolkit does not offer these features, and so in this paper a modified vtkGPUVolumeRayCastMapper is presented. This modified version allows volumetric isosurface rendering as well as receiving shadows from polygons using the usual pipeline.

GPU Volume Ray Casting of two Volumes within VTK

We have modified the current VTK volume rendering on GPU to allow simultaneous rendering of two volumes, each of them with its own color and opacity transfer functions. These changes have led to the creation of two new C++ classes and several GLSL shaders. We explain the modifications made to the original classes and shaders and we discuss possible additional improvements. A C++ demo code shows how to use the new classes.

Enabling ITK-based processing and 3D Slicer MRML scene management in ParaView

This paper documents on-going work to facilitate ITK-based processing and 3D Slicer scene management in ParaView. We believe this will broaden the use of ParaView for high performance computing and visualization in the medical imaging research community. The effort is focused on developing ParaView plug-ins for managing VTK structures from 3D Slicer MRML scenes and encapsulating ITK filters for deployment in ParaView. In this paper, we present KWScene, an open source cross-platform library that is being developed to support implementation of these types of plugins. We describe the overall design of the library and provide implementation details and conclude by presenting a concrete example that demonstrates the use of the KWScene library in computational anatomy research at Johns Hopkins Center for Imaging Science.

2D/3D Multi-Modality Image Registration in Non-Destructive Evaluation

Non-destructive evaluation(NDE) is a group of analysis techniques used in industry to evaluate the property of a material, component or product without causing damage. Among all the techniques, radiology and thermography are two most common methods that are used to inspect the property of the interior of product and combining the knowledge contained in images of two modalites requires the space alignment. In this article, a 2D/3D multi-modality image registration scheme is presented to find the alignment between thermal infrared(IR) image and CT image of a engine blade.

Hough Transform Plane Detector

This document presents a VTK wrapper of an extracted portion of ‘3DTK - The 3D Toolkit’ (http://threedtk.de) to enable a developer to find planes in 3D point cloud data.

A VTK Algorithm for the Computation of the Hausdorff Distance

The Hausdorff distance is a measure of the distance between sets of points. There are many advantages to using this metric compared to other similarity measures. This document describes a VTK class for computing the Hausdorff Distance between two sets of points. The main contribution, compared to other implementations, lies in the definition of the distance not only to the closest point but to the closest point in the represented surface, which yields an accurate measure even between undersampled surfaces. This is achieved by implementing a point-to-cell distance instead of a point-to-point. Furthermore, a plugin for ParaView was implemented, which is also available with the code. After introducing the interest of this distance, the VTK code is explained and illustrated with some examples.