Assign a specific preview color to objects in vb.

We are currently doing a project on reaction diffusion, and therefor we need to have a changing color for a point grid.

An example of reaction/difusion is: https://www.youtube.com/watch?v=3JAqrRnKFHo

Is there a simple way of doing this? We are currently looking at grasshopper attributes and trying to see if we can assign colors this way.

Are we on the right track?

Replies to This Discussion

Permalink Reply by David Rutten on March 3, 2011 at 6:55am

Hi Jens,

if you're going to display thousands upon thousands of points with individual colours assigned to each, you cannot do better than a PointCloud. Grasshopper itself cannot handle PointClouds but you can certainly create them and draw them yourself.

If you're slightly less concerned about performance, you can use a VB script to create a CustomDisplay object (see attached). Note though that whenever you change the code inside the VB component, the old display will still remain active. You'll need to restart Rhino to get rid of it.

David Rutten

david@mcneel.com

Poprad, Slovakia

Attachments:

custom-display.ghx, 42 KB

Permalink Reply by Jens Pedersen on March 3, 2011 at 7:55am

Thank you for the quick reply, but could you elaborate on the pointcloud thing?? Because performance is of huge interest to us.

Permalink Reply by David Rutten on March 3, 2011 at 9:23am

Is the solution I just posted too slow?

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by David Rutten on March 3, 2011 at 9:31am

I just noticed we haven't wrapped the DrawPointcloud method yet in RhinoCommon. I'll add it for the next release.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Jens Pedersen on March 3, 2011 at 9:58am

Sounds good, but no I havnot tested out your proposed solution yet, but i will do that within the next 24 hours, so I can give you a more elaborate answer.

The reason for my interest in the performance aspect is of a more personal manor. But a mino request would be if you could save the GHX file as version 8.004 or .006 so i can read it, the one you attached is 8.007.

Permalink Reply by David Rutten on March 3, 2011 at 2:14pm

I can't, not without installing a previous version which is way too much trouble.

Is the file not opening at all? I don't think I changed the file format much between these versions.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by David Rutten on March 3, 2011 at 2:30pm

I just added a DrawPointCloud method to the display pipeline in RhinoCommon, so come the next release, you can use the attached file to draw large amounts of coloured points as fast as Rhino can possibly muster it.

David Rutten

david@mcneel.com

Poprad, Slovakia

Attachments:

custom-display_pointcloud.ghx, 49 KB

Permalink Reply by Jens Pedersen on March 3, 2011 at 3:59pm

Sounds great.

I will look into the previous file now.

And thanks alot

Permalink Reply by Jens Pedersen on March 5, 2011 at 9:33am

Hi David

I have now played around with the file you initialy send me, and it is unfortunately slower then what is needed. So all i can say is I look foreward to the next update.

Permalink Reply by jm on February 4, 2012 at 7:26am

Hi David

This works fine for me (though the custom displayobject shows as 'old'), but I have a new issue:

The resulting points cannot be selected, when baked. Is there an additional module I could push the output to that would generate a selectable, maleable pintcloud object on 'baking' ?

Thanks !

Permalink Reply by David Rutten on February 4, 2012 at 7:28am

Hi J,

baking means putting the geometry into the Rhino file. Which means they become selectable. The only case in which objects in Rhino 3dm file are not selectable is if they are locked or on a layer that is locked. Is that the case?

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by jm on February 4, 2012 at 8:07am

Thanks David,

Strangely .. no. The resulting points remain in the viewport, even after I close GH (so have been baked in some manner) but appear to remain only as artifacts .. with nothing else in the file and no layers locked, select all results in nothing selected. Very strange - perhaps a legacy issue?

I have the .ghx on the desktop of my computer at work, I will post it here on Monday .. cheers!

James