Cloud display baking ?

Replies to This Discussion

Permalink Reply by Olivier on November 11, 2012 at 7:34am

Tiens une réponse en français :-) Rhino a bien dans ses barres d'outils une sélection par nuage de points, donc je pensais que Grasshopper allait générer un type de géométrie utilisable dans Rhino, mais rien...

Permalink Reply by Yoann Mescam (Systemiq) on November 16, 2012 at 9:11am

Je pense que c'est juste un effet de render.

Un solide rhino c'est juste sa surface-frontière, donc impossible de gérer des effets de flou/transparence dans la masse qui permettraient de modéliser ce genre d'objets.

Le plus proche ça doit être les voxels, et ça n'existe pas dans rhino/gh.

Permalink Reply by Yoann Mescam (Systemiq) on November 16, 2012 at 10:07am

Par contre il y a moyen de simuler ça avec des mesh dont les faces deviennent transparentes en périphérie. Ici ce sont juste des disques orientés vers l'observateur:

Permalink Reply by Olivier on November 17, 2012 at 10:40am

D'accord, merci pour ta réponse Systemiq. C'était juste une question curieuse car j'ai vu la selection par nuage de points dans Rhino, mais si tu me dis que les voxels ne sont pas supportés, ça règle la question ! De toute façon les moteurs de rendu courants n'acceptent que de la géométrie classique en entrée...

 

 

Permalink Reply by Olivier on November 15, 2012 at 7:41am

Please some answer...

I can see points cloud in Rhino selection toolbar, can't Grasshopper generate some geometry when you bake a cloud display ? 

Permalink Reply by Vicente Soler on November 17, 2012 at 1:36pm

The "cloud display" component and a Rhino "point cloud" are different things.

A Rhino point cloud is just a bunch of point objects grouped together. The advantage of using a point cloud is that all points share the same attributes so there is less memory overhead, draws faster and other advantages. It's very useful when you are working with thousands or millions of points.

 

As far as I know you can't bake the "cloud display" component. You'll have to take a screenshot of the viewport while Grasshopper is running.

Permalink Reply by Olivier on November 17, 2012 at 1:51pm

Thanks for the precision Vicente I didn't know the difference. I will certainly give a try to Rhino point clouds, but I must find a renderer that accepts this type of geometry before...

Permalink Reply by Vicente Soler on November 17, 2012 at 2:19pm

I think the cloud display effect is more of a post process effect than a 3d effect.

 

If you want to render it, what I would do is add some small spheres where the dots are and assign to them a material that emits light with a fairly high intensity compared to the rest of the scene (if you don't want to illuminate the rest of the scene with these blobs disable or reduce indirect illumination in those sphere objects or in the material if possible).

 

Render an image and save it as an HDRI (.exr or .hdr file). Open it in Photoshop and duplicate the layer. Use Gaussian blur on the topmost layer and set the blending mode as add (linear dodge). Lower the opacity of the topmost layer until only the bright bits look blurred. (if you want to maintain image exposure lower the opacity of the bottom layer accordingly so that both opacities add to 100 and add a black background).

 

This should imitate the light diffraction that occurs on real world lenses, also known in CG as bloom.

Permalink Reply by Olivier on November 19, 2012 at 12:45pm

Thanks again for all these informations Vicente, perhaps you already know but voxel rendering is previewed as the future in rendering technology. Take a look at this excellent video to have an idea of what i'm talking about : http://www.euclideon.com/video01.html

So my question was simply a curious one about the possibility to generate point clouds with GH and Rhino, until we have access in some years to voxel renderers...

Permalink Reply by Vicente Soler on November 19, 2012 at 5:32pm

If they were purposely trying to sound like a scam in that video they did a great job.

My guess is they really have revolutionary technology and the CEO just wanted to troll guys like Carmack and Notch.

Permalink Reply by Michael Pryor on November 19, 2012 at 1:23pm

Although I found this out accidentally. By setting rhino render to render curves it will render any grasshopper preview. Even clouds.

Permalink Reply by Olivier on November 19, 2012 at 3:30pm

Interesting finding by the way Michael (it works also when checking isocurves) but i think it's a bug in Rhino Render : it doesn't render blue color at all and you can see artifacts in my test...