Sorry for another thread, but I hope those will be useful to other people too...
I'm trying to get a decent overexpanded exhaust plume for my rocket, the kind of effects you see when a launcher gets in upper atmosphere, where the pressure is very low :
On that picture, the rocket is somewhere between 40 and 50 km of altitude (launch video here :
)
I'm pretty sure other have tried to achieve this before me, and playing with particle streams tends to be extremely time consuming. I have issues with those lines of the PARTICLESTREAMSPEC thing :
I've seen the doc but it doesn't help me a lot. I can't even tell if 0 or 1 is full alpha... That's for the first line ; what I understand is that it should map the transparency level of the particle texture from value a to value b, using a function (square root, linear...) or as constant (flat), and the whole thing is function of the engine thrust level (LEVEL), right ?
Also those are a complete mystery to me (PLIN, PLOG) :
What is "sub-range" ? Is it a mathematical or physical expression ? Again I'm not a native english speaker and have no idea of what it could mean. Is it some kind of fine-tuning ?
Then there is the second line : I'd say it maps the alpha level to the "atmospheric parameters" (pressure ?). Here you can choose between "FLAT" (constant), "PLIN" (sub-range linear function ?) and "PLOG" (sub-range logarithmic function ?)
Oh and I'm using D3D9 client.
So if someone already had to deal with those, any advice there ? It could save me a lot of time. ?
I'm trying to get a decent overexpanded exhaust plume for my rocket, the kind of effects you see when a launcher gets in upper atmosphere, where the pressure is very low :
On that picture, the rocket is somewhere between 40 and 50 km of altitude (launch video here :
I'm pretty sure other have tried to achieve this before me, and playing with particle streams tends to be extremely time consuming. I have issues with those lines of the PARTICLESTREAMSPEC thing :
C++:
PARTICLESTREAMSPEC::LVL_SQRT, 0, 1,
PARTICLESTREAMSPEC::ATM_PLOG, 1e-5, 0.1,
I've seen the doc but it doesn't help me a lot. I can't even tell if 0 or 1 is full alpha... That's for the first line ; what I understand is that it should map the transparency level of the particle texture from value a to value b, using a function (square root, linear...) or as constant (flat), and the whole thing is function of the engine thrust level (LEVEL), right ?
Also those are a complete mystery to me (PLIN, PLOG) :
square-root mapping in sub-range
What is "sub-range" ? Is it a mathematical or physical expression ? Again I'm not a native english speaker and have no idea of what it could mean. Is it some kind of fine-tuning ?
Then there is the second line : I'd say it maps the alpha level to the "atmospheric parameters" (pressure ?). Here you can choose between "FLAT" (constant), "PLIN" (sub-range linear function ?) and "PLOG" (sub-range logarithmic function ?)
Oh and I'm using D3D9 client.
So if someone already had to deal with those, any advice there ? It could save me a lot of time. ?