Trouble creating an elevation height map in Grasshopper

Grasshopper
1

Hello,

I’m a Rhino / Grasshopper newbie wanting to create a tool for myself to better identify the height of different surfaces from different angles.

I want to make a elevation heat map, scaled dynamically between the lowest and highest points of whatever geometry I create on a given layer. When I say heat map, I mean something like this.

image

image
image1920×1382 427 KB

I followed this tutorial to create a mesh in Grasshopper constructed around target geometry, colored with a gradient according to the target geometry’s z component, so that, in the grasshopper project I’ve shared & screenshotted below, all surfaces visible in the range of z=3mm should display as blue, but then the gradient doesn’t appear and the geometry stays grasshopper-selected-red.

Screenshot_1
Screenshot_11919×1039 217 KB
// errors: “1. Solution exception:Object reference not set to an instance of an object. 2. Data conversion failed from Surface to Mesh face”
HeightMap.gh (11.5 KB)
DVDCaseTest.3dm (751.4 KB) // the project I was creating this for

I suspect something’s gone wrong in the conversion between brep and mesh. Maybe I misunderstand what breps are?

I would greatly appreciate anyone pointing me in the right direction. Thanks & take care,
Peter

2

Hi @Peter_Schmit ,

I’ll take a look at your script tomorrow but Perhaps this would help you in the mean time?

3

It looks like there’s a lot here that will be helpful, thank you.

What tool in Grasshopper did you use to group and comment on the nodes?

4

Here you have, @Peter_Schmit.

image
image1031×494 40.6 KB

It is very difficult to colour a mesh without having a mesh :rofl:

HeightMap.gh (8.0 KB)

5

Hi @Peter_Schmit , you can use Ctrl+G shortcut to Group selected Nodes and right click on the group to enter a name at the top of the right click menu

6

Thank you, this works great! I didn’t know Mesh Brep existed till now.

What is the purpose of the blank node you’ve inserted between “number” and “parameter?”

7

Got it. This will be useful, thank you.

8

I don’t know which node you are referring to