# K3DSurf : 3d surface generator

DGPF - Deutsche Gesellschaft für Photogrammetrie, Fernerkundung und Geoinformation e.V. - Home Isosurface Surface representing points of constant value within a volume The term isoline is also sometimes used for domains of more than 3 dimensions.[1] Applications Isosurfaces are normally displayed using computer graphics, and are used as data visualization methods in computational fluid dynamics (CFD), allowing engineers to study features of a fluid flow (gas or liquid) around objects, such as aircraft wings. Numerous other disciplines that are interested in three-dimensional data often use isosurfaces to obtain information about pharmacology, chemistry, geophysics and meteorology. Implementation algorithms Marching cubes Asymptotic decider The asymptotic decider algorithm was developed as an extension to marching cubes in order to resolve the possibility of ambiguity in it. Marching tetrahedra The marching tetrahedra algorithm was developed as an extension to marching cubes in order to solve an ambiguity in that algorithm and to create higher quality output surface.

Polygonising a scalar field (Marching Cubes) Also known as: "3D Contouring", "Marching Cubes", "Surface Reconstruction" Written by Paul Bourke May 1994 Based on tables by Cory Gene Bloyd along with additional example source code marchingsource.cppAn alternative table by Geoffrey Heller.rchandra.zip: C++ classes contributed by Raghavendra Chandrashekara.OpenGL source code, sample volume: cell.gz (old)volexample.zip: An example showing how to call polygonise including a sample MRI dataset.Improved (2018) Qt/OpenGL example courtesy Dr. This document describes an algorithm for creating a polygonal surface representation of an isosurface of a 3D scalar field. There are many applications for this type of technique, two very common ones are: Reconstruction of a surface from medical volumetric datasets. The fundamental problem is to form a facet approximation to an isosurface through a scalar field sampled on a rectangular 3D grid. The indexing convention for vertices and edges used in the algorithm are shown below Another example Source code

Implicit surfaces Also known as "Metaballs", "Blobbies", "Soft objects" Written by Paul Bourke June 1997 Introduction Most computer based 3D geometric modelling is done with basic primitives such as lines, planes, boxes, etc. Many smooth and deformable objects are difficult or inefficient to represent with such building blocks, even if primitives such as spheres or Bezier/spline surfaces are used. The following summarises three common methods for creating so called "implicit surfaces". Example Consider the field function D(r) = 1/r2 and a number of control points in 3D space. r is the distance of a point in space to a particular control point. For example if there is a single control point different colour levels will result in spheres of different radius. If the control structure is a line or a plane then the distance r is normally taken to be the closest distance to nay point on the line or plane. Blobby Molecules "b" is related to the standard deviation of the curve, "a" to the height. Meta Balls Notes D.