Geometry Nodes

[Grinsegold]

Blender 3.1 ⍺: "NodesTree" 0.8

[EvertonSchneider]

Hi! I have a question, please, if anyone knows how to do it please let me know…
I want to know if there’s a way to offset or randomize keyframe animations of instances with GN…
Or maybe offset or randomize a mesh cache start frame from an alembic animated object used as an instance…
Or another way… I don’t know… pre-animated objects(location, rotation, scale, shape key, modifiers, shaders… any kind of animated property) distributed as instances but with an offset animation…

[Grinsegold]

#nodevember with Simon Thommes | Day 7-8 | '6 Sided'

In this video Simon shows apart others a method of time shift. Maybe this points you in your direction…

[Miro_Horvath]

Hi there, here’s my quick test of Bisect node patch + explanation how I “looped” Bisect node functionality, someone can find it useful. Enjoy!

Miro Horvath (@MiroHorvath) on X

Miro Horvath (@MiroHorvath) on X

[sanath]

I recently did a video on ivy generator. This thread helped me a lot to understand geometry nodes. Thank you all.

CG Material (@cg_material) on X

[kynu]

I hope you don’t mind a super-simple question from a GN newbie but please help:

Also it seems like that Curve Parameter only works with curve nodes and it outputs zero for any other input (like Scale in Instance to Point). I also can’t quite comprehend why. Shouldn’t it be a red line then if I use it on anything else but a curve node?

So in the end how can I modify the scale of the instances along the curve if not somehow with the above?

[JuanGea]

Why are you using a curve to points?

use a Subdivide Curve, that way you will retain curve attributes, and connect that to points, no need to convert Curve to Points.

Instances can’t have attributes and you are instancing with a scale of 1,1,1, you have to pass the scale to the scale parameter on the Instance On Points, you could do a capture attribute for example, it should work I think.

[kynu]

Thanks a lot @JuanGea! This will help me achieve my ideas tomorrow
Capture Attribute was exactly what I was needing.

But I still needed curve to point because subdividing the curve gives me an uneven point distribution.
Plus - interestingly - the rotation output in the Curve to Point gives me a more precise tangential rotated look

I don’t know why this happens but if I capture the tangent attribute of the curve and use that on the instances, they inherit weird rotation like below (I added a side view to show the curve points are flat in that direction):

[JuanGea]

If you want an even curve point use Resample Curve (or Sample Curve, don’t remember the exact name right now), but don’t use the curve to points, you loose too much information

[dimitar]

Are there list comprehensions planned? I am struggling with all the math to manipulate lists where access to pythonic list comprehensions could suffice.

For example, instancing and rotating curves around a circle, and adding a mesh that completes the revolution. I need to get the first point back in the points list as also the last point in order to apply to set mesh position.

I’ve gotten help over at BA. to get the desired result, but It’s quite a bit more more extensive than being able to add an item to a list.

Similarly, getting the right indices with a combination of module, greater than, and less than, is not as fast or elegant as python list comprehensions like [x:y:z]

[FredSprinkle]

Requesting that perhaps the “reset node” button be moved. It is close to the add>search button (and has the same configuration). I’m always hitting “reset node” instead of add>search for node.

[Miro_Horvath]

Quick test with Mesh Curvature Node patch

Miro Horvath (@MiroHorvath) on X

[Hadriscus]

This is absolutely bloody cool. Had no idea it was being worked on. I suppose you’re resampling the curve and deleting points which have <x deg between them ? I love all these mesh analysis nodes. I’d love to see some sort of pointiness, too. Maybe not the one from Cycles that’s topology-dependent, but something the scale of which the user would have control over.

[modmoderVAAAA]

[Miro_Horvath]

@Hadriscus

I love all these mesh analysis nodes.

Thanks, yes these analysis nodes are pretty handy!!!

Regarding the way I did this test, the thing is that this node calculates angle on the edge between two neighboring faces(green lines) so I first had to use Curve to mesh with a line as profile, once I had angles captured I removed the bottom line edges(blue line) and then I used “Less than” a certain angle to filter out points on straight parts.

[Hadriscus]

Ah yes, ideally that would also return the angle between two edges regardless of the presence of faces. Any technical reason why it needs faces at the moment ?

(I suppose now with the “neighbours” node you could very well use a vector math node to get the angle between two vectors constructed from three arbitrary vertices and use that information to delete points, too)

@Miro_Horvath Thanks for the advice, I suggested that on the diff.

…aaaand

The upcoming curve curvature node will handle that case.

I suppose we’d still have to transfer the resulting attribute from the curve to the mesh-ed curve (in case we need to work with a mesh), so it depends on transferring attribute from curves as well (https://developer.blender.org/T88630)

[Miro_Horvath]

Of course that would be bit more comfortable than doing this workaround, maybe worth asking directly in ⚙ D13366 Geometry Nodes: Add Mesh Curvature Node

[Grinsegold]

My new blend swap location for assets that require nightly builds:
https://developer.blender.org/T93967?fbclid=IwAR1uX-2zkLoBjoqwzzaf41sCz2cWl-aSMhnf6MliWXSH_-YPfjZz4t2wnSs

Enjoy!

[HooglyBoogly]

Hey @Grinsegold, I really like to see people sharing this sort of file, but please don’t user developer.blender.org as a file sharing service like that, it’s not what it’s meant to do.

[Grinsegold]

Do you have space for it in your cloud?