Projecting LineSets

[CaiDurbin]

Hi all,

I'm a new user to Avizo and am mostly using Avizo Green because of its ability to project geographical data in different ways.

My data is mostly stored in NetCDF files and I can make these display nicely. However I'm running into problems when I try to display other datasets.

The example I have at the moment is that I want to display the outlines of the Earth's tectonic plates. Ideally I'd like this to be similar to displaying the borders in the Earth module.

I have the vertices and have used them to create a AmiraMesh file that uses them to define lines that describe the outlines of each plate. Once this is loaded into Avizo I'm displaying it with LineSetView module. There are two major problems with this

1) For plates that have vertices on either side of 180 degree longitude, a line going from -180 to +180 is created to correctly join up the points (see attached image)
2) I can't figure out a way to attach the LineSetView to a projection module

Is there a better way to store line data than an AmiraMesh file with a LineSetView viewer? My current method just doesn't seem to be designed to be projected!

I know that I could solve the first problem by splitting the plates that cause the issue into two, but this doesn't seem like the most elegant method.

Thanks in advance,

Cai

[gwenoletallec]

Hi Cai,

unfortunately LineSetView is not yet supported by the projection mechanism. Nevertheless it has been added to the Avizo requirement database (id 1326) and may be solved in a future version.

Concerning problem 1, you must check crossing lines when they are generated.

How did you generate those lines ?

Regards,

gwenole

[CaiDurbin]

Hi Gwenloe,

Thanks for the reply. That's a shame about LineSet's lack of projection support! Is there an alternative way that I can plot lines that can be projected? Is there a way to replicate the functionality of the Earth module which can show the continent's outlines and be projected?

Concerning the cross lines, I'm creating an AmiraMesh file that contains 12148 verticies which define 12200 lines which together produce the 52 line segments that follow the plate boundaries. I guess that the dumb way to remove the cross lines would be to split any line that crosses the -180/180 degree line into two parts (so not joining the vertices on either side). I was hoping that Avizo Earth would be able to handle this automatically, but then if the LineSet module doesn't yet support projections then it can't do this either?

[wschlei]

Hey Cai,
With your additional connection problem, you will probably have to process your data before you create the LineSet so your connections terminate and start in the appropriate places.

Regarding your projections, I'm pretty sure you can write a Tcl script or an expand code that can take the projection information and the LineSet information to create a new LineSet that is in the projected space. It may not be easy, but it could give you some results before Avizo Earth adds your enhancements.

Wayne