# How to set the normal value of a point on a spline?

How does one go about setting the normals of individual points on a spline? Adding to that question, are these attributes listed on the spreedsheet window?

Part of my confusion is figuring out the math nodes i need to use, and how acctually applying this. In houdini it was easy enough to write a 2 lines of code to get that working, but i would like to know how to achive this with geometry nodes.

I would like this to point outwards. So the first step was attempting to get the distance between the two points before doing more vector math to invert the direction of the last point on the spline.

EDIT

I am aware that i can do this sort of operation. While this works i just want to make sure that i am infact using the most efficient method.

What i am really after is just understand how does once tweak the values of the point on a cuve BEFORE passing it through instance on Points so that the curve is ready with all the desired values. Using the "set curve normal" didnt really do anything when i tried.

• Perhaps I am completely missing your objective, but to rotate the last leave, I would use a Rotate Instances node with the selection mask based on the instance index. But this seems very remote from setting the normal... To change the curve normal, there is the Set Curve Normal node. Commented Mar 15 at 19:34
• And as you will read from this doc, the normals are calculated if needed, so you probably need a Viewer node to visualize these vectors in the Spreadsheet Editor. Commented Mar 15 at 19:40
• Thank you! i should have mentioned that what i wanted to know/learn is how to tweak the values of individual points on a curve BEFORE passing it into the rotate instance node. Similar to how "set position" edits vector values of each point, i wanted to know if there was a node that will take in values to edit specific indexes. Commented Mar 17 at 2:34

## 1 Answer

okay. so number one: the tangent of the spline not the normal so your question is wrong.

number two (the answer to whatyour actually wanted): you could use s switch node between the 'curve tangent' and 'align euler to vector' and use the endpoint selection (or index compared for a custom selection) of the switch and have the unaltered 'curve tangent' as one input and invert the 'curve tangent' with vector math fit the other input.

• Thank you for clearing that up! Very much appreicated it! Commented Apr 4 at 23:48