Hi, I was reluctant in asking this but I cannot find an answer here or on Youtube.
How do I add an “Input Parameter" node? In the Input Panel I click the “+” symbol bit it creates another “Geometry” node. How do I get an “Input Parameter" node?
How Do I Find Specific Geometry Nodes?
I have only just started to play with geometry nodes but as far as I know the is no node called “Input Parameter”. You can use the search function to find specific nodes (click on add and then click search)
There are different input nodes that will help you Input values you want from other objects etc
object info, string, value, vector etc you could drive the string, value, or vector inputs with corresponding values from other objects/data-blocks via a driver or a custom property.
Ok, I see what you want, what he does is add a parameter to the group input node, there is no node called “input Parameter” but you can add parameters to the group inputs and outputs. It is like a shader node group where you can add input and output parameters.
To add a parameter do as shown in the video (hit N and in the group tab you can add and delete parameters)
Edit:
After a few experiments, I can reproduce your problem. Initially when I add a parameter it adds a normal input parameter with a value and will add them recursively as in the video.
If I delete the input parameter, or all of them if there are more than one, the next time I add a parameter it always adds geometry inputs not simple parameter values. Also if you delete the geometry input, it only adds parameters and will not add a new geometry input.
Edit 2:
I found this that will help you:
https://blender.stackexchange.com/questions/220945/how-could-i-set-the-datatype-of-a-value-in-group-input-output-geometry-node
When you have this problem instead of creating a new parameter socket with the + key drag a line from the parameter you wish to create an input for (eg density) to the group input node and it will create a correct input.
Hi, thanks for your reply. I am trying to understand what you said and I watched the video you posted but I don’t get it.
I’m not sure what you mean by adding a dummy node then renaming it. Do I select (Menu > Add > Input) and then link it to the empty node?
In the video he clicks the + and an input parameter is created and then he changes the name to “PebbleCount”. When I click the + it created a “Geometry” node. DO I just change the name of the Geometry node to “PebbleCount”?
Please explain the exact steps for a dummy like me. Can you show a screenshot of how to do this. I am not a mathematician or coder and I just want to complete the step in the video correctly. Thanks.
No if it created a geometry (green) circle output it will refer to a geometry value.
You can add a float value ( a number with decimals) input by dragging a line from any float value input of one of your nodes to the unused circle in the group input node.
Once you do this the result should be this:
Note that the colour of the new output in the group input node is grey. This is because it is a float value (a number with decimals).
Now that you have the new float output in the group input node you can change its name and choose a min max value etc.
You can also unplug it from the point distribute node and plug it into any other grey input socket you have in your node tree. (this is what they meant by dummy input)
Different input values are colour coded to help you know which kind of value they represent, you can see which colour means what in this diagram
So if you drag from a purple input to the group input node it will create a purple coloured circle that can provide vector (xyz) info
Like this:
Note that on the right when you click the vector input there are three float values one for X one for Y and one for Z.
What you need to understand is that there are different types of outputs and inputs that contain different information. As a general rule (there are exceptions) you should always go from grey to grey, purple to purple, green to green etc.
Edit:
With the setup in my example if you look at the geometry node modifier you will see that I created one float input ( a decimal number) and one vector input (three decimal numbers). There is no geometry input because it refers to the geometry of the object with the modifier.
By the way my example does not actually do anything!
Wow. Thank you so very much. I am looking through this and trying to figure it out. I will try to post my result. Thanks. 
