 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
in news:3BE81A6B.547F0694@gmx.de Christoph Hormann wrote:
> I think Ingo has already made such macros, i don't know if they are
> already well tested though.
Yes and no and they are still changing.
Ingo
--
Photography: http://members.home.nl/ingoogni/
Pov-Ray : http://members.home.nl/seed7/
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> On Tue, 06 Nov 2001 10:39:40 -0500, "Greg M. Johnson"
> <"gregj56590[:-0]"@aol.com> wrote:
>
> > This bug-carry-over-from 3.1g could be fixed by changing:
> > PIXEL_COLOR = exp(-d/D) * OBJECT_COLOR + (1-exp(-d/D)) * FOG_COLOR
> > to
> > PIXEL_COLOR = exp(-d/(D+GGG)) * OBJECT_COLOR + (1-exp(-d/(D+GGG))) * FOG_COLOR
> > Where GGG= an infitesimal, just bigger than the smallest number pov can handle
>
> Balancing between floating point accuracy and division by zero is rather not
> very best thing. "The smallest number pov can handle" depends on platform.
> Morover why this addition should be done for all values (even large integers)?
> It is rather bug in parser which allows even "distance -1".
Oh, how about
GGG=1.5*max(smallest_number_for_platform [n]) for all n's?
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
The most efficient solution is just to issue an error message if the
distance <= 0.
--
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Distance=0 ought to be allowed, imho, and give 100% color of fog.
Warp wrote:
> The most efficient solution is just to issue an error message if the
> distance <= 0.
>
> --
> #macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
> rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
> ],13),8)-3,10>#end blob{N(array[6]{11117333955,
> 7382340,3358,3900569407,970,4254934330},0)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Greg M. Johnson <"gregj;-)56590\""@aol.c;-)om> wrote:
: Distance=0 ought to be allowed, imho, and give 100% color of fog.
Wouldn't that be in contradiction with the documentation?
"If the intersection depth equals the fog distance the final color consists
of 64% of the object's color and 36% of the fog's color."
--
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Warp wrote:
> Greg M. Johnson <"gregj;-)56590\""@aol.c;-)om> wrote:
> : Distance=0 ought to be allowed, imho, and give 100% color of fog.
>
> Wouldn't that be in contradiction with the documentation?
>
> "If the intersection depth equals the fog distance the final color consists
> of 64% of the object's color and 36% of the fog's color."
IIMSF, I have no idea what that sentence is saying, but I can make sense of
the equation.
I think that the proposed change to the equation would give an intuitively
pleasing response to what you'd think of if the "visibility were zero" in a
fog.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Greg M. Johnson <"gregj56590[:-0]"@aol.com> wrote:
: I think that the proposed change to the equation would give an intuitively
: pleasing response to what you'd think of if the "visibility were zero" in a
: fog.
I don't understand why is it so difficult to just write a 1e-10 instad
of 0.
--
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Warp wrote:
>
> Greg M. Johnson <"gregj56590[:-0]"@aol.com> wrote:
> : I think that the proposed change to the equation would give an intuitively
> : pleasing response to what you'd think of if the "visibility were zero" in a
> : fog.
>
> I don't understand why is it so difficult to just write a 1e-10 instad
> of 0.
I agree. Stop tweaking formulae/equation, there is already enough bugs in
them already without adding 'pleasant kludge "because I want it to be 0"'.
Rather protect at parse time: if value is not strictly positive, reports Error
and stop parsing.
Or for the strange people which wants to play with negative fog (what is it,
I do not know), protect only against 0.0 , if they are really to be pleased.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
<jer### [at] atosorigin com> wrote:
> Or for the strange people which wants to play with negative fog (what is it,
> I do not know), protect only against 0.0 , if they are really to be pleased.
I never meet such strange people however if it is not forbiden within formula
then I think there should be gate for negative values. Perhaps in the future
some artistic results could be achived with this. Just like not bounding bouding
object is used sometimes.
ABX
--
#declare _=function(a,b,x){((a^2)+(b^2))^.5-x}#default {pigment{color rgb 1}}
union{plane{y,-3}plane{-x,-3}finish{reflection 1 ambient 0}}isosurface{ //ABX
function{_(x-2,y,1)|_((x+y)*.7,z,.1)|_((x+y+2)*.7,z,.1)|_(x/2+y*.8+1.5,z,.1)}
contained_by{box{<0,-3,-.1>,<3,0,.1>}}translate z*15finish{ambient 1}}//POV35
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
If you want that, just go in paintshop pro and create a one color bitmap. Why muck
around in POV for a 1 color bitmap?
"Greg M. Johnson" wrote:
> Distance=0 ought to be allowed, imho, and give 100% color of fog.
>
> Warp wrote:
>
> > The most efficient solution is just to issue an error message if the
> > distance <= 0.
> >
> > --
> > #macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
> > rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
> > ],13),8)-3,10>#end blob{N(array[6]{11117333955,
> > 7382340,3358,3900569407,970,4254934330},0)}// - Warp -
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
|
|
