Where to Begin in Geometry Nodes: Indexes
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- čas přidán 23. 07. 2024
- A few more thoughts about getting started in geometry nodes; I discuss indexes, give several examples of ways to use them, and show how to capture an index or create a custom index using the accumulate field node.
If you haven't seen it, I recommend watching part 1 about the Vector Math node first as it begins with a good overview of my general approach to geometry nodes:
• Where to Begin in Geom...
For more about me, check out my website:
danielhickox.com
My Geometry Nodes and some other tools are on Gumroad:
danielhickox.gumroad.com
0:00 what is an index
0:35 function of index
2:45 index to X,Y coordinate
4:23 capturing an index
6:44 sample at index
9:15 accumulate a custom index
12:29 randomized index
14:22 variable size array
Really love these types of 'fundamentals' tutorials. And the way you visualise them is fantastic. (pendantry warning - plural of index is indices, I think, like vertex > vertices). Thanks for taking the time to make these. I watch all your videos when they're released. (Edit - you say indices at 7:04, hehe!)
Thanks, glad you're enjoting them. I believe both are valid. I think I was using 'indexes' when referring to the sets, and 'indices' when referring to the numbers. eg The vertex and duplicate indexes consist of indices. Whether that's correct or not, I'm not sure.
@@looseEdges haha, who knows...either way, keep meaning these wonderful tutorials!
Thank you for the information. This is a very helpful series.
Regarding future work, it would have helped me if you had stated the goal of various examples before jumping in. And in the more complicated examples, calling out intermediate goals might also have helped occasionally. Now I had to figure that out during your explanation.
Hi , Very cool examples, I am trying to follow your explanation but keep getting lost due to the complexity, variety and speed of the explanation.
To help people who are only starting with geometry nodes, You could limit the number of examples and simply go through the entire build process and explain in a bit more detail what each step does.
At the end, you can quickly show more complex examples to motivate and show all the potential of the topic you are explaining.
You explain well and it is evident you are an expert on the topic, and the examples you present are very well made! I will keep checking your other videos!
Thanks for the lesson, can you share how you build the preview nodes for the index? It would help a lot.
You're welcome! It gets a bit complicated, but the basic idea is to create text instances, 0123456789, then separate the value into its digits and select the correct instance per digit. Of course there's also edge cases, decimals and negative numbers. The node I use in the video is available as the Dbg Print Values node in my Geometry Node Assets if you want to pick that up.
Thank you very much for this indispensable series. What are those 5 folded up red nodes labeled index, island, etc? I wasn't able to quite follow along at that area of the node chain.
You're welcome! Those were different preview nodes which I added ahead of time. They draw the numbers on the example mesh to help visualize what I was talking about, but aren't necessary for the setup to work normally. I made them orange just so I could find them easier.
Gotcha, thanks. I'm still kind of left scratching my head as to how to actually change the index order like you did without those nodes. I'll keep playing with it. @@looseEdges
Well, the index order doesn't change, exactly. But on each vertex (still technically at the original index) you have access to a new attribute which I was describing as a different kind of index. For example, an index in relation to the vertex's mesh island. You're talking about the custom index, at about 10:00, right? @orehasubarashi
How did you display the vertex position of each vertice, how do you access the window on the top left screen?
To draw the points, I am using the Dbg_DrawPoints node from my GeoNode assets: czcams.com/video/H3wFDVpmRJA/video.htmlsi=_-PbxGIo0YEB51h8 A basic version of it is just instance on points with an icosphere.
The editor in the top left is called the Spreadsheet tool, you can switch any view region to it via the Editor Type menu at the far left hand side of the header.
What did you use to render the indices numbers in the viewport ?
I made some nodes that display them: czcams.com/video/H3wFDVpmRJA/video.html
I am trying to do a simple index shift...so taking the preset starting index 0 and shift it to some other position...mainly useful for aligning the 0 vert on two morph objects. I am familiar with the math to redistribute verts, invert them, but not so sure how you would set a new starting position for index 0. I don't think that was mentioned in this video, so can you point me in the right direction?
If I understand correctly, you have two objects with the same topology, so vertex 0 on one is equivalent to vertex 0 on the other, and you want to move the verts in one of the objects to the position of the verts in the other object. You can do that with a Sample Index node using the Index node as the Index value. Here's an example file: danielhickox.com/uploads/morph_example.blend
@@looseEdges Thanks so much for sharing this sample file! This isn't exactly what I was trying to do, but it's very interesting to see the setup you used none the less! I am extremely close to what I was going for. I was originally trying to flip the index ordering, without moving the starting point (index 0), which I was able to figure out. What I am not sure about is if you want to set some other index (index 7 for instance) to be the starting point 0, so that you can better align the indices for a shape morph, what is the best way to offset your indices? I am also very curious about the samples you used in this video, is there any chance I can get the project file(s) somewhere to dissect your setups further? I am following along on my own but there are definitely still some gaps and I really want to understand this stuff to the core. Thanks again for sharing!!!
@@SJ98296 Sure, I think I still have the file, I'll see if I can find it. I guess I'm not quite following what you're trying to accomplish. Do you want to join my discord server so you can share an image or drawing of what you're going for?
discord.com/invite/6rdD5jQtNn
@@SJ98296 Here's the index examples file: danielhickox.com/uploads/djh_index_node_examples.blend
@@looseEdges great, thank you.