I'm trying to make leafs falling of tree.
I have pig.png - containing photo of a leaf, with background marked s 100% 
transparent, and hf.png containing png grayscale height-map for leaf.

Now, how can I create a leaf? I'm using height_field, and results are quite 
good, but how to:

1) create an mesh from an height_field (do I have to build mesh manualy 
i.e. as grid of say 200x200 points, height of each determinating by using 
pigment_eval or simmilar? Bot still it would be hard to calculate normals 
for smooth_triangle)

2) how can I cut away this black (100% transparent) background - how can I 
make it 100% transparent?


about 1) - if ther isn't any macro doing so yet, I would like to try coding 
it, hwo should I calculate normal for point P[x,y] when height of it's 
neightbours are P[x-1,y] P[x,y-1] etc..., and distance between them is some 
"h" vlue.

-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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On 23 Jan 2004 13:23:13 -0500, "Rafal 'Raf256' Maj" <spa### [at] raf256com> wrote:
> 1) create an mesh from an height_field (do I have to build mesh manualy 
> i.e. as grid of say 200x200 points, height of each determinating by using 
> pigment_eval or simmilar? Bot still it would be hard to calculate normals 
> for smooth_triangle)

IIRC familiy of HF* macros do that. See shapes.inc standard include file (and
manual).

ABX

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abx### [at] abxartpl news:joq210dmca761mvhibm1ffd67baq7u3r7q@4ax.com

> IIRC familiy of HF* macros do that. See shapes.inc standard include
> file (and manual).

Thanks, I'll.

And bout cutting off backgound - using transparent 1 for black kolor will 
*not* help, because then still finish would be used (specular, reflection).


Btw, how about 6-th component for color - ignore? <r,g,b,f,t,i> 

It's purpose would be to work on finish-based-colors as transparent works 
on colors.

I.e. rgbfti <1,1,1,0,1,0> would be a red with 100% trasmit, so only finish 
(i.e. specular reflections) will make surface visible, and
rgbfti 1 would make it totaly invisible.

But I dont know is there sense to implementing it, because it's looks like 
realy lots of work imho?


-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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spa### [at] raf256com news:Xns9479C94105AB5raf256com@203.29.75.35


Well, the solution was realy easy - just use water_level in hf and black 
background will dissapeare


-- 
#macro g(U,V)(.4*abs(sin(9*sqrt(pow(x-U,2)+pow(y-V,2))))*pow(1-min(1,(sqrt(
pow(x-U,2)+pow(y-V,2))*.3)),2)+.9)#end#macro p(c)#if(c>1)#local l=mod(c,100
);g(2*div(l,10)-8,2*mod(l,10)-8)*p(div(c,100))#else 1#end#end light_source{
y 2}sphere{z*20 9pigment{function{p(26252423)*p(36455644)*p(66656463)}}}//M

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Hi Rafal,

I understand that you have already solved your problem, so this
may not be relevant anymore. I am working on some algorithms
to create and modify meshes. Up to now that is only closed
surfaces, but I can see no real problem in extending that to
non-closed surfaces, like leaves. If you have these pig.png and
hf.pnf files for me, I could try to generate a mesh of, say,
200 triangles for you. No garantees, however, it is something
I want to do anyway someday, but time is scarce (and I have
apart from my work a number of POV related problems to work on),
so even if I can do it, it might be ready long after you finished
this image. On the other hand it could be ready by monday.
You never know ;)

	Andrel

Rafal 'Raf256' Maj wrote:
> I'm trying to make leafs falling of tree.
> I have pig.png - containing photo of a leaf, with background marked s 100% 
> transparent, and hf.png containing png grayscale height-map for leaf.
> 
> Now, how can I create a leaf? I'm using height_field, and results are quite 
> good, but how to:
> 
> 1) create an mesh from an height_field (do I have to build mesh manualy 
> i.e. as grid of say 200x200 points, height of each determinating by using 
> pigment_eval or simmilar? Bot still it would be hard to calculate normals 
> for smooth_triangle)
> 
> 2) how can I cut away this black (100% transparent) background - how can I 
> make it 100% transparent?
> 
> 
> about 1) - if ther isn't any macro doing so yet, I would like to try coding 
> it, hwo should I calculate normal for point P[x,y] when height of it's 
> neightbours are P[x-1,y] P[x,y-1] etc..., and distance between them is some 
> "h" vlue.
>

Post a reply to this message