Import a path from a csv file and display it on a mesh?

Question

I have created a mesh (.obj) and run several A* searches on it which yields to me a .txt file where each line is:

x,y,z
x1,y1,z1 ...

I would like to find a way to ideally import these as a single object, showcasing the route my A* search took along the mesh, but haven't found anything that seems to support that such a request is even possible. Am I missing something here?

EDIT: Here are some screenshots to highlight the data I am working with to hopefully make the question clearer.

Image1: This is the mesh my process makes (the holes are expected), where the obj consists of the vertices and faces which compose it.

Image2: After running A*search, this is the type of output I have, where the path is just a list of vertices visited. I am able to index them to the structure that holds their coordinates for the proposed line I want.

Shortest path between start and end nodes on mesh found. ['start', 50502, 50504, 49191, 49193, 47885, 46610, 46612, 45361, 44131, 42932, 41745, 41747, 49583, 39442, 38322, 37213, 36176, 35120, 34086, 33055, 32041, 31045, 30068, 29098, 28140, 27195, 26270, 25351, 24602, 23779, 22490, 21352, 20240, 19154, 18098, 17064, 16059, 15082, 14134, 13214, 12536, 12576, 13495, 14441, 15417, 16421, 17454, 18511, 19592, 20704, 21844, 23009, 24176, 24923, 25846, 26775, 27711, 28688, 29658, 30638, 31625, 32633, 33659, 34694, 35744, 36810, 37900, 39020, 40152, 41305, 'end']

Image3: This is what I am hoping to accomplish. A line drawn on the mesh from each point to point.

Would a better title be: 'How do I import a path from a csv file?' ... Also, FYI, the GN Shortest Path node, (which is a Dijkstra search) will let you trace your paths directly, inside Blender. — Robin Betts, Dec 06 '22 at 09:34
I’d like it to be imported and displayed as line segments that I can change the color of for visualization purposes. Since the requirements of my project are that all computation regarding the build and search of the mesh needs to be self contained, I am only using blender/mesh lab for visualization and mesh design measurements. — Thomas, Dec 06 '22 at 11:11
What's a line segment? Curve, edges, polygons? I would recommend a curve, bc. you can easily change thickness and shape. But coloring different segments depending on the csv. might be tricky. But please provide more details and perhaps screenshots. — Frederik Steinmetz, Dec 06 '22 at 11:18
Are the output numbers the indices of vertices or the coordinates (x,y,z)? Anyway, you can write a Python script to import the values and mark the corresponding vertices of the mesh. Or you can create a mesh line from them. Then convert it to a curve as you wish. — Blunder, Dec 07 '22 at 18:37
@Thomas ??? https://www.youtube.com/watch?v=-NOqNMWukl0 https://blender.stackexchange.com/questions/273207 — vklidu, Dec 08 '22 at 11:27

vklidu · Answer 1 · 2022-12-12T20:40:33.447

version 01 - Shortest Path node

Robin Betts's comment is right - most direct solution could be use Shortest Path node under Geometry Nodes system ... you can get idea here or here. Since your Q is aiming to a different approach I'm not going to go further here.

version 02 - Text file (CSV) - Index of Vertices

You can copy values from your Image2 (I suppose values represents vertex numbers - indices) and place them into text editor. At row 1 type some name (like "short-path" or what ever) and run find/replace operator to change comma with space to enter character, so your text file end up with single value per row. Save as .csv format.

This file you can import into a Blender with Blender Spreadsheet Importer mentioned in version 03.

Now when values are imported as vertex attributes, select your terrain object and use this geometry node tree to distribute vertices at their locations ... (big thanks to @RobinBetts answer again)

At last, to connect vertices into a path ad Realise Instances node and node group seen in last image of version 03. Note: the "B" value is just a limit of vertices to be connected.

version 03 - Text file (CSV) - XYZ

Import CSV data of XYZ as Attribute for Geometry nodes. Each row contains three columns of X Y Z values. For simplicity I used just three vertices. -the first at loc 0, 0, 0, second at 1, 1, 1 etc.