.About

GLNebula is a system designed for the real-time visualization of planetary nebulae models (and in general, any static one-component scalar field, provided that the data is in the correct form). produced by three-dimensional photoionization codes such as Cloudy 3D.

GLNebula is free software and is licensed under the GPL

It uses three files: each one represents the emission values of one ionized element inside the nebula. The files are arranged in a cubical grid with one scalar per cell (see the File structure section of the manual), by using particles to represent each cell, real-time framerates can be achieved with large grids while keeping the appearance of being a full volume.

Each file is assigned to a particular color channel, so the scalar values of every element correspond to a certain color intensity, which coupled with color blending, transparency and texture support, preserve realism (see the screenshots section).

Due to the fact that the models tend to be of a very high resolution and that the program is using some OpenGL extensions not supported by integrated GPUs, a relatively modern video card is most recommended (a GeForce 2mx or equivalent is the minimum).

GLNebula is written in C/C++, using OpenGL and fltk for the user interface.

.Features

• Real time visualization of large models
  
  
• Free user-controlled camera: By operating the mouse, the user can rotate the model and zoom in and out of it.
  
  
• Two particle types: GLNebula uses camera-oriented quads (billboards) and point-sprites coupled with display lists to provide fast performance.
  
  
• Full visualization parameters control: you can modify the transparency, particle size and type, channel saturation, treshold value, etc. to adjust the model to your needs.
  
  
• Session management: Save the current visualization for posterior use, or restore a previous one.
  
  
• Snapshot support: Write a png image of the current display window and optionally embed a caption with relevant information to the visualization (session name, data files used and their assigned color).