Hi there,

long time no see, long time no trace.
Unfortunately I didn't have much time "to POV" but finally I could manage to
do some major improvements to the fern macro.
First of all I made a whole wing as a single mesh. This increases slightly
parsing time (since I have to transform a lot of triangles "manually") but
has a huge advantage that I can save a whole fern wing as an auto-generated
include file. This speeds up parsing time dramatically when including the
generated file instead of re-computing it each time.
Additionally there are now two models of fern-wings: "standing" and
"hanging" ones. The first style is used for ferns growing on an mostly flat
ground, whereas the second style is used for ferns growing on a hill or
stone (free hanging wings).
Both styles are now controlled via the "wing age" instead of the number of
leaves on them (this is calculated automatically).
Several preview modes are supported to adjust the wings and camera quickly.
The small leaves can be controlled in their "level of detail" (LOD) which
reduces the number of mesh triangles of the leaf and it's middle stem and
simplifies the texture to speed up rendering.
For a wing you may define a "center of interest" which will control the LOD
of the leaves automatically. Objects near to this point will have more
details than objects farther away.

I think this will be the last fern images for a while since I will
concentrate now on the other participants of my scene.
Therefore I post this few pictures demonstrating the fern macro features.
Please note that there is still no complete -fern- macro but only a -wing-
and -leaf- macro. Anyway I already have some scenes building up a fern where
the usage can easily be seen.

Thank you very much for your interest and feedback!
As soon as I have some viewable results of the other objects I will (of
course)  post them here to get your opinion, so stay tuned :-) I really
enjoy the discussion here.

Ok, lets get to the pictures.

This one is a rough preview (preview mode 2) showing only the stems of the
wings (thickness is 3 times exaggregated)
The colour of the stems is twice as bright as usual to make them visible
even in dark scenes (ambient 1, diffuse 1)
This mode is very useful to adjust the stems in general.

Processing time: 2'19" (both, parse and trace) (No AA)

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Attachments:
Download 'fern_p1.jpg' (35 KB)

Preview of image 'fern_p1.jpg'

The second mode uses normal stems and adds already some kind of "leaf". The
preview leaves are flattened cones but already similar to the final leaves
(according to angle and size).
I changed the camera position to peek underneath the fern. The wing
arrangement is identical to the previous picture.
Note the dead leaf lying on the ground in the lower left corner.

Processing time: 1'55" parsing, 1'53" tracing (No AA)

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Attachments:
Download 'fern_p2.jpg' (49 KB)

Preview of image 'fern_p2.jpg'

This picture is a final trace showing a lot of different features at a time.
The camera position is like in the last preview so you can easily compare
them. (please note that the dead leaves are contrrolled randomly and vary
between the pictures).

Feat1: the two wings in the middle of the picture (almost pointing out of
the pic) are cut off. This can be simulated easily by the so-called shape
parameters which control the size of the small leaves as they get placed
along the wing's stem.
Feat2: auto-LOD. You can see a differnce in the level of detail between the
left and the right hand side wings. This is due a misplacement of the LOD
center from the camera position (to make it noticeable)
Feat3: leaf age. The ded leaves on the ground were created with the same
macro as all the others leaves were created. just the aging parameters were
different
Feat4: leaf age. compare the ripples of the small leaves between the lower
and upper wings. lower wings are older and have therefore older leaves.
Feat5: damage of the leaves. note the small scratches in some leaves. easily
controllable by giving a probability for this effect.
Feat6: lost leaves. there are some missing leaves in some wings but this
can't be seen easily here.

Processing time: 26'33" parsing (first time parse, creation of include
file), 23' 09" tracing (No AA)

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Attachments:
Download 'fern_full1.jpg' (46 KB)

Preview of image 'fern_full1.jpg'

The second final trace using the include file created in the step before.
I changed the camera position again. You can see the difference in the level
of detail clearly.

Procesing time: 3'04" parsing, 5'33" tracing (No AA)

of course, any feedback is welcome!

best regards
SY

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Attachments:
Download 'fern_full2.jpg' (51 KB)

Preview of image 'fern_full2.jpg'

It looks great! I like it a loot, congratulations. Perhaps the camera is too
close to the fern? I would like to see how it looks a bit farther away...

Very good work!

Fernando.

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You are right, the camera was really close. I wanted to check the details,
especially the LOD settings.
Here's another picture showing the whole thing.

best regards
SY

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Attachments:
Download 'fern2.jpg' (33 KB)

Preview of image 'fern2.jpg'

Here it is.

regards
SY

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Attachments:
Download 'fern3.jpg' (40 KB)

Preview of image 'fern3.jpg'

It looks VERY realistic. Congratulations, it is beautiful.

Very good work!

Fernando.

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This would be quite convincing in a scene!

-- 
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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> This would be quite convincing in a scene!

Yes, I'm working on it. But for now the fern is the only thing already
finished. As you can see I am not satisfied easily with my own work so this
will take some time :-)

But if anyone would like to add a fern to his scene I can provide the latest
code for the macro together with a small description.

regards
SY

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