/usr/share/doc/dx/help/dxall208 is in dx-doc 1:4.4.4-7.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | #!F-adobe-helvetica-medium-r-normal--18*
#!N
#!N #!Ropacom Opacities Component #!N #!N #!N The
"opacities" component plays a role similar to that of colors components,
except that it specifies a floating-point opacity for rendering. Its interpretation
differs depending on whether the connections represent a surface (triangles or
quads), or a volume (tetrahedra, cubes, and so on). In the
surface case, the opacity is a number from 0 to 1
specifying the opacity of the surface. In the volume case, the
opacity represents the instantaneous attenuation of light per unit distance traveled.
Like the colors components, it can be position- or connection-dependent. #!N
#!N The interpretation of "colors" and "opacities" differs between surfaces and
volumes. For surfaces, a surface of color #!F-adobe-times-medium-i-normal--18* c[f] #!EF and
opacity #!F-adobe-times-medium-i-normal--18* o #!EF is combined with the color #!F-adobe-times-medium-i-normal--18* c[b]
#!EF of the objects behind it resulting in a combined color
#!F-adobe-times-medium-i-normal--18* c[f]o + c[b](1 - o) #!EF . #!N #!N For
volumes, the "dense emitter" model is used, in which the opacity
represents the instantaneous rate of absorption of light passing through the
volume per unit thickness, and the color represents the instantaneous rate
of light emission per unit thickness. If #!F-adobe-times-medium-i-normal--18* c(z) #!EF represents
the color of the object at #!F-adobe-times-medium-i-normal--18* z #!EF and #!F-adobe-times-medium-i-normal--18*
o(z) #!EF represents its opacity at #!F-adobe-times-medium-i-normal--18* z #!EF , then
the total color of a ray passing through the volume is
given by: #!N c = integral to infinity from - infinity
c ( z ) 'exp' (- integral to z from -
infinity o ( zeta ) d zeta) dz #!N #!N #!N
#!N #!F-adobe-times-medium-i-normal--18* Next Topic #!EF #!N #!N #!Ltall210,dxall210 h Color Map and Opacity Map Components #!EL #!N #!F-adobe-times-medium-i-normal--18* #!N
|