> > also how about a different path, and perhaps some camera motion, try to
give
> > some impression of speed - perhaps whizzing past the camera (which then
> > judders slightly) etc etc
> that wouldn't work with the shader.  I tried it, but it didn't look good.
> Shaders aren't the perfect way to create smoke, but they are fast compared
to media.

You mean, the camera can't move?  Ooh.... :o(  Anyway you've demonstrated
something that has increased my interest in Povman, and you've done much
better smoke than I've ever seen in Pov.. If you'd explain just the basic
idea, so I can learn how to do it with media eventually ...or would it be
great to use glows? (if Pov3.5 had them...)  Negative glows or glows that
aren't fully transparant..

Hugo

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> You mean, the camera can't move?  Ooh.... :o(  Anyway you've demonstrated
> something that has increased my interest in Povman, and you've done much
> better smoke than I've ever seen in Pov.. If you'd explain just the basic
> idea, so I can learn how to do it with media eventually ...or would it be
> great to use glows? (if Pov3.5 had them...)  Negative glows or glows that
> aren't fully transparant..
Nono, the camera can move, but the method I used to "detect" the edges of the object
isn't
really perfect.  Things wouldn't look good if the fireball was coming towards the
camera,
because too much of the object would be considered as an edge, so it would be almost
completely transparent.
Well, more or less.  It depends on the object you use of course...

I don't think you could learn how to do it with media by knowing how I did this smoke.
Media and shaders are a totally different feature, although very simple media-effects
can
be simulated using shaders.  Using media might be a better idea for smoke, but it's
rather
slow, and shaders are more fun :)

I've been thinking of making smoke with glows, but there is one little problem: glows
are
visible through other objects.  As far as I know, there's no way of letting a glow get
blocked by an object.   So you'd have to check for visibility for each glow.

I'll post the source of the shader and the animation to p.b.s-f, so anyone who wants,
can
play with it :)

cu!
--
camera{location-z*3}#macro G(b,e)b+(e-b)*(C/50)#end#macro L(b,e,k,l)#local C=0
;#while(C<50)sphere{G(b,e),.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1
;#end#end L(y-x,y,x,x+y)L(y,-x-y,x+y,y)L(-x-y,-y,y,y+z)L(-y,y,y+z,x+y)L(0,x+y,
<.5,1,.5>,x)L(0,x-y,<.5,1,.5>,x)               // ZK http://www.povplace.be.tf

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