opengl modelling rocket flame and vapour trails with particles
Does anyone have any guidance for coding an approximat开发者_如何学JAVAion for the particle stream coming out of a jet engine (with afterburner) in opengl using particles drawing using vertex buffers / 4f color buffers?
I believe there are two aspects to this problem:
The colour of the light as particles exit the jet engine as a function of temperature and some constants relating to the type of gas being burnt. This article leads me to believe I will need some sort of array for the temperature / color conversion curve. Apprently hydrogen burns at 2,660C in oxygen and 2,045C in air whereas jet fuel burns at 287.5C in air. (but the temperature of jet fighter afterburner can reach 1700C somehow)
The vapour trail behind the rocket / jet which will be either white with alpha for the water base vapour trail if the rocket is in atmosphere. Also I believe my assumption is correct that this would not be necessary for a rocket burning fuel in space. The vapour trail will simulated as tiny water droplets which are much larger than the wavelength of visible light, so they would scatter light achromatically. As water itself is colorless the resulting color would be white?
Also I am looking to model this from a birds eye perspective so it does not need to be a full 3D model. So the positions of the 10 or so pilot lights around the afterburner cone for example could just be approximated as maybe 5 linear points.
Depending on the level of detail you require, you may want to simple use a textured cone coming out of the yet engine. If you want to go for a full-blown particle system (which for a jet engine does not appear necessary to me) then you might want to give each particle on the stack a bunch of properties like speed (vec3), size, gas type and age.
Make a loop to process each particle each time your game loop goes around. For each tick, your simulation would then change the speed and size as the particle gets older. You should make a functions that determines the look of the particle according to its age and gas type.
At its simplest, this could make colored particles fade, enlarge and speed down as it gets older. Is this what you are looking for?
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