"Tim Riley" <timothyrileyatnetscapedotnet> wrote

> Found this link in the Rhino newsgroup:
>
> http://graphics.uni-konstanz.de/~luft/ivy_generator/

Looks promising, but the display is horrendously slow (<0.1 fps).

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"Jeremy M. Praay" <jer### [at] questsoftwarecmo> wrote in message 
news:45fad9ca$1@news.povray.org...
>
> OMG!  This is amazing.  Now I guess I know what I'll be doing this 
> weekend.
> :-)
>

It took quite a few tries to figure out how to make it work, but I thought 
this turned out pretty good.  Now I just need to include it in a "real" 
scene.

After importing into Pose-Ray, I had to also create transparency maps, 
otherwise the shiny leaf surfaces became square.  I'm not aware of another 
way around this.  I also had to rotate the leaves 180 degrees, and I may a 
few other more subtle changes.  But for the most part, it was not difficult 
to do.  I recommend reading the readme.txt before you use the Ivy Generator, 
though.  It will save you a few minutes of trying to figure out the 
interface on your own.

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Attachments:
Download 'ivy2_POV_scene.jpg' (113 KB)

Preview of image 'ivy2_POV_scene.jpg'

"Jeremy M. Praay" <jer### [at] questsoftwarecom> schreef in bericht 
news:45fbf6f5@news.povray.org...
> "Jeremy M. Praay" <jer### [at] questsoftwarecmo> wrote in message 
> news:45fad9ca$1@news.povray.org...
>>
>> OMG!  This is amazing.  Now I guess I know what I'll be doing this 
>> weekend.
>> :-)
>>
>
> It took quite a few tries to figure out how to make it work, but I thought 
> this turned out pretty good.  Now I just need to include it in a "real" 
> scene.
>
> After importing into Pose-Ray, I had to also create transparency maps, 
> otherwise the shiny leaf surfaces became square.  I'm not aware of another 
> way around this.  I also had to rotate the leaves 180 degrees, and I may a 
> few other more subtle changes.  But for the most part, it was not 
> difficult to do.  I recommend reading the readme.txt before you use the 
> Ivy Generator, though.  It will save you a few minutes of trying to figure 
> out the interface on your own.
>
Yes, I also found out about the transparency maps. I had not yet discovered 
the rotation though. The output files can become fairly large (I have now 
one of about 200mb) and that takes time to process. So it may be a good idea 
to do it in rather small bunches of ivy perhaps.
Also, what I found disconcerting is that the sliders do the contrary to what 
you expect. So, increasing the leaf slider decreases the number of leaves!!! 
and so for most of them. It may be me though....

Thomas


Thomas

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"Thomas de Groot" <t.d### [at] internlDOTnet> wrote in message 
news:45fc094b$1@news.povray.org...
> Yes, I also found out about the transparency maps. I had not yet 
> discovered the rotation though. The output files can become fairly large 
> (I have now one of about 200mb) and that takes time to process. So it may 
> be a good idea to do it in rather small bunches of ivy perhaps.
> Also, what I found disconcerting is that the sliders do the contrary to 
> what you expect. So, increasing the leaf slider decreases the number of 
> leaves!!! and so for most of them. It may be me though....
>

Yeah, I just started playing with the sliders.  "leaf probability" is 
another one.  If you increase it, there are fewer leaves.

Nevertheless, I'm having a ton of fun with this.  And I've already begun to 
incorporate it into an existing scene that I was working on.  :-)

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Works perty good after tweaking a bit.

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Nice! Thank you Tim!

Although the leaves don't like atmospheric media and spotlights, they look 
good in a bog standard area-light.

   ~Steve~

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An overgrown statue.
A file size of 223 mb for the ivy (2mb for the statue).
In v3.7:
parse time: 81 CPU seconds (1 thread)
trace time: 6 minutes (2 threads)

There are a number of issues one has to take into account:
- the x-axis orientation is switched between the Generator and Poseray. This 
may give problems with assymetrical objects. Just inverse then the Ivy 
object along x.
- As said by Jeremy already: watch out for the transparency mapping.
- several of the sliders work differently from what is expected.
- make sure your obj file is correct. I started using obj generated by Silo 
(which work perfectly otherwise) but in the Generator they showed only half 
the triangles as opaque. Solution was to pass the obj file through Poseray 
and export again as an obj file. Worked correctly.
- The generator by default turns the normals inwards.

Thomas

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Preview of image 'GrowingIvyTest.jpg'

OK. Some further testing.
The axis orientation is posing problems. Should be simple though  :-(
I thought simply scaling x by -1 would be enough, but it isn't. There is 
more involved. IvyGenerator is right-handed I suppose, so exporting in 
POV-Ray orientation through Poseray an object not centered on the origin, 
you may need to:
scale <-1,1,1>
rotate <0,-90,0>
translate <a given amount over x, maybe z>

At least, that is what I come up with.

Thomas

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"Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
> An overgrown statue.

Nice image, Thomas!  I'd like to see further work on this.

KW

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"Kenneth" <kdw### [at] earthlinknet> schreef in bericht 
news:web.4600fa14e71b54f1d41bc31b0@news.povray.org...
> "Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
>> An overgrown statue.
>
> Nice image, Thomas!  I'd like to see further work on this.
>

Thanks Kenneth! I am working on a couple of image for the 'before-after' 
topic where the ivy will be present. As well as the statue by the way, but 
not overgrown.

Thomas

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