Geometry instancing Puns

I am a beginner and do not understand geometry nodes very well (especially the 3.0.0 attribute nodes)

I am trying to create a scene in blender by instancing a geometry node over a set number of points. My hope was to take a node group and give it random values for each instance. The issue I'm having is in blender 2.93.7 I can't find a way to instance a geometry onto points (can only find object to points via point instance node) and in blender 3.0.0 I can instance the geometry but cant assign the random values for the geometry.

The random values range from grid sizes to attribute randomization percentages.

A workaround in either version will work for me however a solution for 2.93.7 is preferable.

https://preview.redd.it/6qtarnof3ra81.png?width=769&format=png&auto=webp&s=4195a0c8b63dc241618b43ec9d71a9b716dc11a7

The photo shows (an incorrect) solution that I would like to have if it is possible. The Building Geometry needs to stay procedural for my use.

Thank You.

Let's say I have an object with a material, and I instantiate a bunch of cubes on it. Is there any way to make those cubes automatically use the same material as the original object?

I'd imagine this would be a bit tricky implementation-wise, as instancing happens at vertices, but material assignments are a property of faces

According to Vulkan Programming Guide by Graham Sellers, one should be able to set the invocations of the geometry shader via specializations constants.

I tried the following in my geometry shader without success:

layout (constant_id = 0) const int NumInvocations = 1;

layout(triangles) in;

layout(line_strip, max_vertices = 6, invocations = NumInvocations) out;

What would be the correct way to achieve this?

I have this very simple geometry node setup (this is my first time using them, and I am in 2.92 btw) and am instancing the building objects around the plane. They are clearly colliding. I don't want to have less of them but I also do not want them to collide. How can I edit the point instancing so that they don't collide? Thanks guys.

https://preview.redd.it/1yq3i0d8igo61.png?width=2326&format=png&auto=webp&s=b48acb1748dd71b3d35f1ede60c769b6ce44a952

Let’s say I have a collection with three simple objects: A, B, C. I have a plane, plane1 subdivided a couple times. I define a geometry node system where I instance the collection ABC on that plane (but without using a point distribute node). The result is any one of A, B, or C appears on every vertex of the plane.

I have a large plane, plane2. I want to use geometry nodes in the same way as above to instance plane1 on the vertices of plane2.

However when I do this the distribution of objects A, B, and C remains the SAME for every instance of plane1 on plane2.

How can I achieve this with a different distribution of the collection ABC for every instance of plane1?

I know the seed value socket can probably be used to achieve this but I’d need a geo nodes equivalent of the “object info random” or “random per island” output from the shader nodes. This doesn’t seem to exist as far as I can see.

(I have tried using an array modifier on plane1 and in this case I do get a different distribution of ABC for every object. The issue with this is I don’t get as much control and also the node system disappears suddenly although I think may be a bug from geo nodes being brand new)

Hello! I'm building a simple Flip simulation and I'm trying to instance a Box for every particle in the simulation. My end goal is to have a liquid made of boxes, but I'm stuck at the instancing part. I tried to use a Pop Instance Node in the DOPNet but still no results. Any idea how I could achieve this? Any help is greatly appreciated!

I formatted the question and sample code in a blog post here: http://richiesams.blogspot.com/2014/05/how-to-do-you-implement-geometry.html

Here's an excerpt of the main question:

So at some point in the graphics pipeline, you have a list of models that need to rendered. Normal scenario:

1. Set the CBuffer variables
2. Call DrawIndexed

Simple. Ok next scenario is if the models are instanced. Yes I can use DrawIndexedInstanced, but my question is: What's the best way to send the instance data to the GPU?

Hi all,

I want to make an input for my instances on points node to control what percentage of the instances are shown.

I understand that to do this I need to use the 'Selection' connector of the node, but am unsure what to plug into.

I need it so that I can control the percentage of instances, whilst also having the instances shown be on random points.

Any advice is greatly appreciated, thanks in advance :)

The title is somewhat explanatory, but here are the full details:

I am trying out geometry nodes, but am really new to them.

I want to make a basic pine tree using 4 objects; Tree base, Main Branch, secondary branch, pine needle. The pine needle will be applied to the secondary branch, the secondary branch to the main branch, and so on.

I figured that if I have the geometry node formation for one object I can duplicate it to the rest.

As you can see by the image, I managed to get the pine needle to the secondary branch. However, I need the pine needles to be distributed uniformly around the branch, and every time I rotate the needles they only rotate around their local axis.

I thought that Rotate Euler would solve this issue by rotating around the object axis instead of the local axis, but it keeps rotating around the local axis. I don't know if this is an error with Rotate Euler or if there are more nodes I need to use in order to correct this issue.

If anyone knows how to solve the issue I will be grateful.

Geometry Node Setup

I am trying to take a collection, using the collection info node, and randomly pick a object from that collection. I can't figure out how to do this, or if its possible in 2.93. I would like to be able to add a random seed, that I could change, which would change the object that is selected from a collection.

So I have a simple geometry node group, I make grass spawn from a plane that's subdivided with geometry nodes. I tried raycast but that doesn't care about instances apparently. What can I do to get rid of this issue? Also the kicker is I want to have the whole instance disappear if it touches the object, not just intersecting area. The plane isn't dense enough for weight painting.

Hi all,

I want to make an input for my instances on points node to control what percentage of the instances are shown.

I understand that to do this I need to use the 'Selection' connector of the node, but am unsure what to plug into.

I need it so that I can control the percentage of instances, whilst also having the instances shown be on random points.

Any advice is greatly appreciated, thanks in advance :)