NoiseMap Forums

NoiseMap Software => Hints and Tips => Topic started by: roger on November 23, 2016, 06:49:48 PM

Title: How can I speed up the generation of the 3-d view?
Post by: roger on November 23, 2016, 06:49:48 PM
The short answer is that NoiseMap only creates a 3-d view from the part of the model that is loaded when you start the 3-d generator, so it will be much quicker to create a number of small 3-d views rather than one large one: in any case, these are usually more convenient to use.

The 3-d view consists of thousands of triangular 'facets' each with its own orientation and surface texture. These have to be generated from the noise model, which only has points and lines representing the objects in the model.  The first part of the process is to work out where the corners of the triangles are going to be placed.  The 3-d generator shows this step as 'Generating Vertices'.  With a big model there can be thousands or even millions of these.

Then the major work starts - that of joining the vertices so as to fill the model with adjoining triangles in such a way that all the vertices are included but there are no gaps between triangles nor any overlaps. Each triangle also has an orientation so that the viewer app knows which way it is facing, to allow the visibility and illumination of the surface to be correctly presented. There is a huge amount of work in creating the facets, because the objects in the noise model, and thus the vertices, are located entirely randomly. This makes it necessary to check every vertex against every other vertex so that the nearest one is found when creating the facets.  Of course, once a vertex is surrounded by facets, it has been 'used up' so it is not considered further.  You will notice that the faceting speeds up as it progresses, for this reason.

The ground surface takes much longer to create than any other part of the model, because there are so many contour points in it.  If you can simplify the contours, 3-d generation will be much quicker.

The 3-d viewer is a fantastic tool for checking and presenting noise models.  However, for quick checks, you will find Cross-sections and View-As-Colour to be very productive tools.