3D field visualization

[Clash]

How I can implement this 3D visualization using OpenGL?
This is something like fog colored by temperature.

[NeXEkho]

Build a texture containing the heat colours and overlay it using GL_BLEND and a quadrilateral that covers the entire screen. You can either blur it to make it nice and foggy or rely on GL's bilinear interpolation to make a not-quite-so-nice blur.

[Clash]

Thank you very much.

Build a texture containing the heat colours

Can you explain a bit detailed - what kind of texture I should build (3D?) and how I can do it. May be you can advice a good example.

[Dark Photon]

Build a texture containing the heat colours

Can you explain a bit detailed - what kind of texture I should build

Take a look at the legends here:

* http://www.opendx.org/inaction/datam.../uk-insure.jpg
* http://www.opendx.org/inaction/datam...l/walmart5.jpg
* http://www.opendx.org/inaction/medic.../eyeCornea.jpg
* http://www.opendx.org/inaction/datam.../neuralnet.jpg

OpenDX contains one of these. VTK probably as well (both open source). Other commercial packages such as AVS no doubt too.

[Clash]

Take a look at the legends here:

Thank you, but I did not understand what you suggested.
Are you talking about using some library? May be this is a good way, but I already have program that do not use any graphic library and I just search a recipe to do 3D filed visualization like showed on example picture.

[Dark Photon]

Thank you, but I did not understand what you suggested.
Are you talking about using some library?

No. You can see the color order in the legend, right? Slap those in a texture, turn on GL_LINEAR interpolation, and use that as your value-to-temperature-color lookup table.

[Clash]

No. You can see the color order in the legend, right? Slap those in a texture, turn on GL_LINEAR interpolation, and use that as your value-to-temperature-color lookup table.

This is not a problem. I already have value-to-temperature look up table, but I do not know how to show this color "fog" using OpenGL. What feature of OpenGL should I use to draw that color "fog"?

[ZbuffeR]

glTexSubImage2D the temperature value, and draw a textured quad with it.
Put some alpha transparency for good measure, a simple glColor4f(1,1,1,0.5) should do the trick with default GL_MODULATE texture blend mode.

[Clash]

glTexSubImage2D the temperature value, and draw a textured quad with it.
Put some alpha transparency for good measure, a simple glColor4f(1,1,1,0.5) should do the trick with default GL_MODULATE texture blend mode.

Thank you for your advice. I only cannot understand how I can get 3D picture from 2d quad. I should draw a lot quads, right?

[ZbuffeR]

In your second picture, the one with fog temperature, it looks only a simple textured quad was added.