Subject: Re: Ripples
From: [email-masked] (Jim McCabe)
To: [email-masked]
Date: Mon, 8 Aug 1994 07:37:39 -0700

Allen Hastings replies:
>
>The texture sizes define the dimensions of the ellipsoid containing the
>wave sources.  The center of the ellipsoid is defined by the texture center.
>The wave sources are randomly distributed within the ellipsoid (unless you
>have only one, in which case it's at the center).  As always, the texture
>size and center parameters are measured in distance units (usually thought
>of as meters).  Wavelength is also in units, and wave speed is in units per
>frame.  Amplitude controls how strongly the surface normals are perturbed.
>I had hoped this would all be in the manual...
> 
>- AH

Thanks, Allen. Most of what you described is in the manual, which I've read 
quite a few times. Unfortunately, I'm still in the dark concerning the 
Ripples Bump Map. Does the Texture Size ellipsoid determine the volume 
outside of which the ripples stop, and does it have nothing to do with the 
dimensions of the individual ripples (which are determined solely by 
Amplitude and Wavelength)? Also, when applying the texture to a flat plane, 
I'm visualizing that the ellipsoid full of randomly placed wave sources is 
intersected with the plane, and the resulting slice is mapped onto the 
plane. Therefore, if, for example, the plane is the XZ plane, and the 
ellipsoid is a circle of radius 1 at (0,0,0), and the sources are randomly 
distributed, then it is possible that if you specify three sources of 
amplitude, say, .1, you might see anywhere from one to three wave sources on 
your plane since the others might be centered somewhere past +/- 0.1 on the 
Y axis. Am I heading in the right direction ? Thanks.