Select What You Want in Geometry Nodes - Blender Tutorial
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In today's lesson we're going to be diving deep into selections. Learning this well will be transformative to you rprocedural workflows, not just in Geometry Nodes but across all procedural systems.
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Correction: Accumulate Field node's "Total" output does not tell you how many elemtns have been counted, it returns the sum total of whatever values it has counted up. When the Value is 1 as in mine, that means it added 1 per element which is why I worded it that way.
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Contents:
00:00 - Intro
02:12 - What are selections?
03:19 - Booleans
06:16 - Joining Booleans
07:55 - What is an index?
08:45 - Vertex Group Selection
10:14 - How floats are interpolated
11:30 - Float to Integer node
13:16 - Selections with Empties
16:27 - Index-based Selections
19:12 - Selecting a grid row
20:50 - Selecting a grid column
23:06 - Duplicate Index
24:55 - Mesh Island Index
26:10 - Index per point per island
28:11 - Splines
29:05 - Spline Parameter Index
30:47 - Index on Spline Domain
32:50 - Position-based Selections
35:19 - Normal-based Selections
37:15 - Raycasted Selections
40:10 - Curve Attribute Selections
42:20 - Curve Corner Selections
47:08 - Expand Selections
53:35 - Flatten Region Exercise
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@Erindale , another tip 😁: when you were checking to see if any selection were too small you didn’t have to separate the mesh (which is some i try to avoid. [messes up my indices, attributes, extra compute time, etc]). what you could do is the less well known node family called the "face groups to boundary edges" and "boundary edges to face groups". You first use the selection as a face group which you convert to boundary edges and then you convert it back; this gives you an ID per selection island, which you could usr with the accumulate field etc.
Huh I did not realise there was a boundary edges to face group node now 🙌
@Erindale I'm thinking about how many nodes you used and how two nodes could probably replace almost the whole thing 😄
I use to think that I'll never get a grasp of Geometry nodes. But after watching this, I'm now certain of it.
😂😭
@@Erindale I still watch all your videos in hopes to get that aha moment some day. Thank you for putting out quality contents for free. I'll definitely be purchasing your Simulation nodes course once I get the hang of this.
@hereb4theend I recommend joining my discord server so you can ask people directly when you run into issues. It'll help accelerate you
@@hereb4theendthis stuff fits squarely into networked muscle memory, so what you'll want to do is go from the top down. Understand the broadest purpose of geometry nodes, and then understand the broadest purpose of the different categories of them, and then look at a bunch of things people have done with them, focusing on the results. Then without even knowing exactly what all the nodes are, you have a framework for what you have and haven't seen done, and where you'll most likely find the components you're looking for to get the effects you want, along with the names of some of the ones people use all the time like instance on points and join geometry. Then it's a matter of drilling some stuff into your head over and over until you might not realize how much progress you made, so if you get imposter syndrome or feel like you're not doing anything, it might help to keep objective progress reports. I sometimes feel like I haven't done a lot, but then I remember when I was even clunkier, and all the surrounding circumstances I tend to not factor in as much as I should, and I build a little confidence and get my head back in gear
The nodes are more scared of you than you are of them
32:17 - "Just a little bit of esoteric knowledge..." The very _best_ kind of knowledge there is!
This video is pure gold in the form of zeros and ones travelling through the internet!
Selections… the topic i most need for GN! Many thanks.
Thanks! I think this is going to help a few people out here
Correction: Accumulate Field node's "Total" output does not tell you how many elemtns have been counted, it returns the sum total of whatever values it has counted up. When the Value is 1 as in mine, that means it added 1 per element which is why I worded it that way.
Is it possible to force blender´s geometry nodes to NOT calculate specific regions?
@@blendcreator exactly in that boolean math where erindale showed and told you can use them by ENGLISH there is a NOT option ;)
Your Boolean NOT is going to be the inverted selection but you still need to evaluate the mask everywhere. The selection sockets on Set Position, Store Named Attribute etc do limit the computation of the node operation just to the selection but, unfortunately, you can't get around evaluating where the mask actually is.
one of the best, if not THE best, yet underrated, advanced yet prescinded geometry nodes tutorial. So very useful and valuable info! Thanks erin!!!
Thank you so much! This tutorial was extremely helpful. 😺
this is great, thank you!
Wait this video for a long time! Really thanks
Many thanks! these kind of videos that compile methods are easy to get back to
Been waiting for a tutorial on geometry nodes that goes over selections for quite some time now, Thank you!
I could learn so much from you man, this was more than enough to properly introduce fundamentals for geometry nodes! Keep up the great work!
Insane tutorial.
Great lesson -- thanks for sharing.
Gonna send people this way for geometry node tips this is super useful reference material thank you :)
This is wonderful! Thank you very much for sharing your knowledge while explaining the thinking behind the choices. I've learnt a lot from you!
Great explanation.
This is going to be super useful thank you!
Thank you!
Thank you... So much ❤❤❤❤
This is great, I love the breakdown of how/why things are working the way they do.
Thank you, glad you like it!
Thank you for this incredibly informative video! NOW I feel like I’m starting to get it. I can’t wait to check out your courses
Thanks! Enjoy!
You legend. This is the single best geo nodes tutorial I have seen and I wish I had it years ago.
Great tutorial, this is not a very intuitive way to work but with practice, I can see myself using this. I really hope that GN developers make things easier in the future !
Absolute gold video
Thank you! This is an incredibly useful walk through of how selection works!
Glad it's useful!
Thanks so much Erindale, always wondered about selection in geo nodes. Very useful!
My pleasure!
Oh wow @somartist you also do blender besides painting?
yes, I always been a secret 3d artist too, and it comes in handy for various projects I have :D@@edwinluthfisaputra107
The tutorial was amazing as always, but finding out the most common and still yet least spoken issue and making a tutorial for it was even more brilliant! great job and thanks a lot dear Erin :)
Haha thank you 😁
10/10 thank you so much for this!
i was looking for tutorials on this and Boom! this was posted minutes before i typed in my search A Big thank you!!
Nice! The secret art
This has really turned on a lightbulb in my mind. I've learnt so much, thank you
I’m glad! Good luck
You are officially the best. Others abide our questions, you stand alone.
Thank you so much
Great Tutorial. Thank you! To be honest, your tutorials keep pushing me to the limits, so I always need to watch them at least two times. Once I get it, it's really satisfying...
I’m happy they’re useful to you!
Wished I watched this waaaaaay sooner! really love this, the way you explained and went through this was great -- didn't even feel like a 1 hour video. Been following your other tutorials as well and have been trying to learn bit by bit through different use cases but really glad to have come across this as a general knowledge tutorial which I feel is incredibly helpful also once you start moving into more specific use cases where tutorials might not be available for.
Thank you! Yeah as much as I love making the specific tutorials, it can be difficult to extract the general lesson as a learner
Super good, must watch video!
Thank you, enjoy
Really great video. Just to note that for the 'expand selection' part, the Blur Attribute also does the job when you put it through a Vector Math (Ceiling) node, so no need for the Repeat Zone. (or you can multiply instead of ceiling for a more circular expansion).
Super useful tutorial. Had to watch a few times and keep Geo nodes open on Blender to try selection tools at the same time.
This is definitely something worth learning well
I learn tons of new stuffs about geonode in your video,thanks a lot,by the way,I'm a big fan of you from China
Thank you so much!
oh shit this was exactly what i was looking for, for one of my projects. thanks a lot! No one explains this complex node stuff better than you erin..
Thank you! Yeah it took me some time to get fluent with geo nodes and I realised that it's really all down to being confident in what selection you're making
Thank you so much!!!
I really hope they will add a list node and list methods soon, great tutorial again! very grateful
There's definitely been some murmurs around that but I don't see it happening soon 🥲
非常有意义的示教，GN第一事，选择要操作的内容。太赞了👍👍👍👍👍
Thanks so much!
你会说中文，你是如何理解教程的？
@@danialsoozani 我是中国人😁即便只是看视频，也毫无问题，演示的图形本身就是非常明确的语言！
Thank you, thank you, thank you! I am leaning Geo Nodes and up until 40th min I could understand and replicate almost everything from memory, but after that it become much much harder for my level - anyway will go systematically with you other tutorials and resources and try again in few weeks.
a really concise roundup here thanks... i think it mostly just clicked for me now prob the last tutorial i need (he says) the docs on these are so bad (literally almost 0 examples, just a small description, if you're lucky a "hint"), so this is great
❤Jeeesus criest this is the BIBLE for starting work on geonodes... you are a hero. thanks a lot!!
Great video. Figuring out certain things about geometry nodes -- selections, how to conceptualize working on fields and operating on them with some precision -- has been the biggest hurdle so far. This helps.
Thanks for this! Seeing what’s harder for people to grasp is very useful for me making content
As always , you're the only boss of the Geo nodes . 😊
Thanks so much
friend you really explain very, very well thank you very much for sharing your knowledge God take care of you
Thank you!
Thanks for the brilliant tutorial, I did not realise the subtle power of the accumulate field node until I watched this, cheers!
Yeah it's amazing! A lot of advanced setups use it
I love you man, I love you...
Gold. First, I'm so happy that I've managed to figure out a lot by myself, but there are things that couldn't be possible without you and other authors on YT. Mostly because of terminology. The math itself is not that hard, but learning the names of math ops, as a kid, in Croatian still gives me headaches when learning GN watching the tuts English. It's a lot easier for me to build node systems for terrains because I am not limited by numbers that much and that's where my brain has all the artistic freedom it needs, and, basically, I often make tools from my experiments and happy accidents. Anyway, for the 100th time - thank you.
I feel very lucky that I learned maths through Blender. I only really have the visual understanding of the functions. I’m glad the contents useful!
I'm going through this again and thinking how you, as an educator, would have a special place in the world of architecture. Maybe even as an architect. I know you had that sort of content in the past, but maybe getting more specialised in that area is even better than focusing on games/cg market/industry. Just a thought.
very useful~ good. thank you
Thank you!
nice tutorial :)
grand. selections are an area where I seem to invent new struggles every time. this is super valuable and I'm sure I will trigger a few hundred plays in the near future. thanks for sharing!
That's great to hear! I see a lot of people struggling with selections, both beginners and professionals. You are very much not alone
@@Erindale thanks, glad the devs added a way to visualize selections a few versions back. Paired with this video, I should be able to get up to speed
excellent
Thank you!
Hey, great topic and deep dive. I noticed the pile of books behind you and since im a huge fan of 7 habits of highly effective people, i wondered what the rest of the books are.
In this stack I have Building a Second Brain by Tiago Forte which I definitely recommend. Also Deep Work and So Good They Can't Ignore You (by Cal Newport), The Freelance Manifesto (Joey Korenman), Eat That Frog (Brian Tracy), and Getting Things Done (David Allen)
I've not read them all but they're my motivators when I fall off the horse
Awesome tutorial. This is something what I was looking for. Giving a general information that can be used for problem solving instead just solving one problem. I'd like to see more tutorials like this in the future. This helps a lof for people like me who wants a deeper and behind the screen understanding for the nodes and math in general. I'd like to know more about the topology nodes as well. I'd like to know how you switched the connected socket from 'x' to 'z' so fast at 23:24.
Alt+S cycles the input noodle through the sockets
It's hard going but I think I'm starting to get the hang of the concepts. I like the way it teaches the fundamentals, not just press this, press that but explains the thinking behind it. But I'm a long way from being able to do it on my own, maybe one day!
It’s all just practice and repetition. The foundations will all start clicking together ✌️
wahooo, I have zero knowledge in programming. But this course is just master class. Thanks a lot ! This base will let us learn geometry node. Great explanation, considering I'm French native speaking. again Thanks !!
Good luck with your learning!
@Erindale , Quick tip. use the blur attribute node for expanding selections. no loops needed 😉
I mention it but the iteration count correspond perfectly to the expansion steps?
@Erindale at least when I used it, if you compare greater than 0 and you converted it to a float, I haven't maxed out before blender slowed down significantly. and yes, the iteration matches the steps perfectly. it uses topology to smooth, so smoothing depends on topology density and always follows the topology
(To be clear, I haven't maxed out selection expansion at all even after blender slows down)
🔥🔥🔥
I think this might be the one video that will make everything click! 100x (Y)
I hope so!
Hozier of the Blender world. I will not elaborate
Hey Erindale! Great tutorial and I learned a lot. Thank you very much! I have a question regarding selecting the UV Seam. I'm trying to select the UV seam to use it to split the edges in GN. My setup is basically getting the UVmap attribute from the group input and then run it through an evaluate on domain node with data type as vector and domain as points and then send it to a compare node and compare the UVmap original vector with the new evaluated one with a compare node with the Element-wise mode and Not Equal operation and capture the result from the compare node with a capture attribute node set to Boolean Data Type and Face Corner as Domain and use it as the selection for the Split Edges node. So far it seems to work in selecting the seam if the seam is going through a full loop cut but if it’s a partial loop cut it seems like it doesn’t select the final edge of the seam and it stays welded. I tried many different ways but I couldn’t get to select that last edge. Any idea how to get around this issue? Thanks in advance.
This is kind of a hack and it won’t be as performant as purely doing it via data, however, if you capture the original positions, split all the edges, set the positions to the UV map locations, merge by distance, and then set the position back to that original position, you’ll have the split edges where the seams have split the UV islands
@@Erindale This will work for now. Thank you so much.
Great tutorial as always, thank you for that. I have a question - why does the float to integer node even exist when the exact same operations can be done with the regular math node? Is it more lightweight, or is it something else?
Integers are not susceptible to float rounding errors. It's easy to think of numbers as numbers like how we see them but computers have to do some trickery to actually store them. That's why on the compare node when it's set to float, equals, there's an epsilon value. Asking a float when it equals exactly itself will often fail due to some small decimal part being different. Integers also take less memory to store so it can be an efficiency gain, especially on very dense geometry
@@Erindale Thanks a lot, that cleared it up for me.
Hey Erindale! Great tutorial and a lot of info. Thank you very much! I'm currently trying to make nodes for converting text objects to Neon Geometry. And stuck on the Neon ends. Which have to be bent backward from the letter plane. Main issue after i;ve deleted segment by using Endpoint Segment node for defining that segment. I have to move the ends backward. That is not a problem too with Set Position + Endpoint Segment nodes. But I also need to move that ends straight under the next points at the curve to make a straight angle between ends and letter plane. And I can't catch that, how do I get the location of the next points and use it for the positions of the ends. I'm a beginner here and might I've chosen the wrong way?
One potentially easy option would be to convert to mesh without a profile so you have an edge, use the extrude mesh node to extrude back as far as needed and then convert to curve to continue. You could even use the filet curve node to round that corner to the extrusion
Thank you Erindale! Many ways, and some of them are not so oblivious at my level. Looks like I have to learn the basics better. Then I will see.@@Erindale
You are amazing! Are you a mathematician?
Nah I learnt everything from Blender!
Vid is great 👍 but what about any inner parts like a bottle?
You could use raycast to see if you will shoot out into empty space or hit the other inside face
Another superb tutorial, thank you. Using the Normal method, with either a Direction or Dot Product comparison, I can select lines (/faces) of latitude on a sphere or torus - but I can't figure out how to adapt that to select lines of longitude. Any ideas?
Take the normal, multiply by (1,1,0) to negate the difference in vertical direction and then normalize so each band has the same vector on it. The you can compare against a horizontal vector to make the selection
@@Erindale Thanks - bit strange!?! , but that works well enough!!
Thanks Erindale! Legend. I have a question... how would you grow a selection on a curve/edge? The technique you showed only seems to work on faces.
Use a blur attribute node and ceiling the output. Each blur step will walk one more element
Thank you! I think that GN is a amazing tool, but people at Blender foundation should start thinking about a more intuitive way of working with data. In my opinion lists should be the way to go. For example, Grasshopper for Rhino is just way easier to manipulate your data.
It’s a different methodology and both Houdini and grasshopper (which is essentially a pythonic data flow) were considered. Once you’re fluent with GN you’ll find that a lot of things work a lot better and more intuitively because you’re specifically not needing to work with the data yourself. It’s handled inherently in the workflow
Hey, @@Erindale. Thanks for your feedback! Yeah, I think I'm trying to figure out GN logics with a pythonic dataflow in my mind, as you said. I think it make things a little harder, but I'll figure it out with time. By the way, your tutorials are helping a lot! Thanks!
🙏
I can't seem to get around comprehending the accumulate field node.. What's the idea behind it? 🤔
It's a sum loop. It will look at the attribute on each mesh element and add it up in order. Johnny Matthews' has a good video on it (he made it)
Suzanne from procedural nodegroup... how come?? You saved somehow the original vertex positions to values? or or or what? :)
Yeah no clever shortcuts, I just copied all the vertex positions into a node group 😂 still no idea why she wasn't included in the mesh primitives
first time seeing ur tutorial on my laptop (instead of my phone)... Holy fuck thats a huge cursor...
Go back to your phone 😭
@@Erindale dude my phone was dead i couldn't wait to watch ur video so i just used my laptop instead ahahaha
excellent as always - but what is the difference between a 'float to integer' node and math node set to floor? don't they both just truncate the thing (by which I think I mean chop off the bits after the decimal point)?
The difference is how the data is literally stored in memory. Floats have floating point precision error so it just depends on your requirements. Functionally they’re so similar that if often doesn’t matter. Storing as integers will be more optimised
@@Erindale thanks Erin - six minutes to reply to a question on a four month old video is very impressive :)
How would you store a selection made with an empty cumulatively as the empty is moved around?
Using simulation nodes and adding the selection to the current named attribute and storing it with the same name
Thank you! @@Erindale
Why isn't the Edge Angle node called Face Angle?
OK, I've just realised the answer to my question. It's the angle at an edge (at the junction of two faces)...
Bloody good, by the way.
@25:36 - How do you make each island have a different color? Mine are all grayscale...
Make sure that you are connecting your viewer automatically with the hotkey so that it makes the right kind of socket. You see when I first drop on the white noise node that it shows black because it had been previewing an integer before. Then I recreate the connections on the float (grey socket) and then click again to get to the color (yellow socket)
@@Erindale It worked - thank you very much.
my viewer node turns off whenever I select the empty. how can I keep viewing it?
Make sure you pin the node tree as the viewer is disabled when the node tree is not in focus
@@Erindale thank you!
So many hotkeys were used, yet I can't see key press :'(
Yeah this was while Screencast Keys addon was not working with the new Blender version
Warning about selection using Indices: The devs warn not to do this. Their backend is whack, and when they make edits to nodes, it could result in completely different indexing. I have an 18,000 node model that uses selection by indexing exclusively... and Each version of blender breaks at least 3 nodes... The one that pretty much made me quit using blender: Split Edges worked perfectly... and Hans went and redid it so that it *RANDOMLY* reindexes the *entire* model for no reason. When I asked him not to... he added notes to the documentation not to use indexing as selection. -_- Purposefully breaking nodes just rubbed me the wrong way to the point of losing all motivation to work on any Blender related project. Years of work... broken by someone else... on purpose. (He didn't purposefully break my node, but he did purposefully change the node to explicitly rearrange indexes, which breaks any nodegroup that uses index as selection... and refused to care that it broke years of work.)
Indices in Blender have always been a bit hit and miss. If you ever did anything with python building meshes outside geometry nodes you'll have run into the same problems.
zzzzz......
Literally same I pass out while reviewing these edits