Re: Muddy 3D mixer
Re: Muddy 3D mixer
- Subject: Re: Muddy 3D mixer
- From: "Timothy J. Wood" <email@hidden>
- Date: Sun, 15 Sep 2002 23:49:39 -0700
On Sunday, September 15, 2002, at 11:02 PM, Kurt Bigler wrote:
[...]
What I am really saying is that if I am not mistaken, input and output
amplitudes and distances must have some units involved, otherwise
there is
no sensible meaning for a falloff "gain" of 1 occurring at a certain
distance.
[...]
The header file says the following for the distance and gain
parameters:
// Input, Metres, 0->10000, 1
k3DMixerParam_Distance = 2,
// Input/Output, dB, -120->20, 0
k3DMixerParam_Gain = 3
So, it looks like they do have units for these 'documented' (these
are probably in the SDK docs too since the comments from the headers
seem to be copied there in general).
BTW, a good fitting curve for the last graph I sent out seems to be:
Distance = -0.05717778641878812351251326617784798145294189453125 *
Gain**0 +
0.376349270558307524847663216860382817685604095458984375 * Gain**1 +
0.064629691295884306168062494180048815906047821044921875 * Gain**2
+
0.000420259942668125175031790252688779219170100986957550048828125 *
Gain**3
(I just fed the midpoints of my error bars into a least squares
approximation :)
Clearly some real documentation is in order on the mathematics used
in the rendering of the 3D mixer.
-tim
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