Salut Pokiz.
J'utilise beaucoup les courbes sous sketchup, illustrator, photoshop, AutoCAD et Rhino... le seul qui dispose de presque tous les outils est Rhino...
Sur Sketchup, il faut se contenter des courbes interpolées de Fredo. Il y en a quand même un sacré paquet et ça répond de manière assez intuitive à la majorité des besoins... Il faut juste choisir l'outil adéquat : Bezier, Spline, F-Spline, Courbette... le choix est large, et les points éditables après coup.
Il y a un petit logiciel libre sur Windows pour modifier ce paramètre : http://www.framasoft.net/article3556.html.
Mais il est délicat d'aller changer systématiquement les paramètres de clavier. Le mieux est de bosser en cm et non en mètres sur les modèles architecturaux par exemple.
Thomthom : it's Sketchup itself wich can produce a "fog effect" in the style panel, but non of the external renderer I tried could use this settings directly (Podium, Artlantis V1, Twilight, neither Kerkythea which has an internal volumetric light effect).
So, let's mix pictures and photoshop them...
Or, use this depth effect tutorials from sketchup, but using V-ray, it should be easier to use the innerVRayZDepth Render Pass
However, those tutorials couldn't give a correct volumetric light. Kerkythea, Vray, Maxwell and other could do it for advanced user... good luck
False, there is a fog effect, but it's not quite like a realistc volumetric light... 
This is really good ! Thanks. 
It should be greater to have a dialog box with :
Iteration : number of reflexion of ray (bypass for infinite ray, and warning for more than 10 ?).
Number of ray : draw N initial rays from the focal point (warning for more than 30 ?).
Planar : option to constraint reflexions in a plan for early analysis of acoustic reflexion in the section of any room.
I guess I would be to busy to work on this, like dozen of other script that are waiting...
By the way, good job TIG, thanks.
From my point of view Kerkyhea is the best free renderer for Sketchup...
But, if you have problem with Mac Install, you should take a look to complete version of Podium... which has the nicer learning curve I ever met... You simply put the setting on noisy setting... then let the computer turn during the night, and come back with some beautifull pics like this.
But really, what Ecuadorian said is right, it's depend of how you are rendering...
Just choose one, or two, and learn them, depending of the compatibility with MAC, the licensing price, and the way you want to use it.
C'est un bug fréquent quand les divisions des profils sont plus fines que celles du maillage de la surface : faire un surface sur un profils avec 150 arrêtes mais seulement 10x10 divisions pour la grille peut conduire à des problèmes.
Seules solutions à ce jour de mon côté :
Pour autant, je serai ravi de voir apparaitre un outil type soap skin sur les courbes de kirill2008, mais il y a encore du boulot... Presque plus vite fat d'apprendre Rhino 
Sinon, il faut attendre les améliorations de plugin Skin, ou utiliser le plugin d'extrusion de TIG. La surface obtenue n'est ni gonflable, ni éditable, mais parfois, un courbe lissée avec les bons profils fait l'affaire.
On the spline extension of fredo, you can chose the number of segment you want and edit them after creation.
But once you had extruded surface and spline with the standard sketchup tool : non way back !
I guess quadro fx have a deep acceleration effect on SU.
I use at my office an Old workstation (6 years) which kills all the recent dell precision we have bought on sketchup... The only difference is a quadro fx1400 with professional drivers...
I'll give you tomorow some precisions about the specifications of each computer.
As far as I know, Nvidia quadro with professionnal drivers are really better than Geforce for Autodesk application, CATIA, Sketchup and other CAD program... And a major part of this difference is due to driver's professionnal optimisation.
I am quite impressed seeing how lightup have improve since the first time I use it...
I guess I should try it again, but metropolis render give me very good results in Kerkythea and podium.
Adam, is it possible to extract some insulation numerical values (eg : on a desk) after the calculation ? I would like to use it in a lighting optimization script.
Can't get this work well. Seems to be some problem to read my points.txt file !?
Command input :
@unknownuser said:
...Sketchup 6\Plugins\Qhull\qhull.exe" TI points.txt v Qbb Qj o Fv
Command output :
@unknownuser said:
qhull error: could not open file "points.txt".
While executing: | qhull TI points.txt v Qbb Qj o Fv
Options selected for Qhull 2003.1 2003/12/30:
Could anybody help and or develop some direct and realtime approximate voronoi calculation in sketchup ? Like soap-skin-bubble plugin ?
File from the debug.skp file given by a4chitect... Do not work with my qhull.exe ?
For this, you would have to see fredo6 and his script about drawing on curve. Since he did scripted a way to draw and extrude curved surface, he probably could help you with a way to copy multiple hexagons on a surface (quite hard on free surfaces 
).
However, I think the best way to do it is probably to use kerkythea or a renderer soft with displacement mapping support... You will just have a bad time to align those textures of yours, but I thinks it's better than cracking your brain on ruby ?
Good luck
WHOA, So I have to give a try to the free versionof SU7, but, I think my computer will begin to say ARRGHH... (quite old... 
)
Did anyone was able to do the same for groups or any volume ?
This is quite a big idea, but implicit geometry (NURBS, Blobs, and other forms that could be redraw from control points, lines and faces) is really far from what sketchup is doing today. However, there are a lot of soft which are actually doing what you are talking about :
But, I recognize that Sketchup interface is easer than Rhino one... And Rhino or Moi do not have any free version. So this could be a great improvement for SU7 : providing a free version which keep a clear interface and user-friendly workflow, while allowing edition on complex NURBS and spline.
Note that if anybody want to model a NURBS the way it is suggested in the first message, then it could be usefull to implement T-spline instead.
T-spline are more powerfull than spline if you want to edit the object in the way you do with a polymodeler : extruding, pulling, stretching, adding details all the time. Just have a look here.
For those who are searching, there was a quick job on Bezier surface plugins for sketchup : http://groups.google.com/group/Ruby-API/browse_thread/thread/0e044d3b1f7124e5
PS : Chango70, plot-paris, I guess Soap-skin-Bubble don't use Nurbs or spline maths, there is probably just a relaxation calculus of a fixed grid of points, so it's hard maths and physics, but not the same that defines NURBS and Spline.
I am going with pbacot on the fact that we could use simple way to "scale" objects and preserve some specific characteristics, but it's not always possible ! For example, in my window components, glass and frame are two different groups !
There are two things that could be really cool with the completion of the parametric plugin:
One of the biggest problem with this way of design, it's that it usually works with explicit history and modifiers compilation for all the objects ! What's New in SU7 ?