1
$\begingroup$

General Explanation to My Question

I want to display a curve defined by parameter equations using a shader node tree:

$$ f(x)=\left\{ \begin{aligned} x & = f(\theta) \\ y & = g(\theta) \\ \end{aligned} \right. $$

To achieve this, I have to input a precise range of $\theta$ in the Shader Editor.

The situation

I've created something interesting: a screen that displays a Lissajous curve. Here is how my node tree look like: The node tree

The node tree mainly comprises of 2 parts:

  1. the coordinate grids
  2. the curve (or, to be more precise, "the dot")

Here is what my texture looks like on a plane (2m * 2m, layed on XOY Plane) :

The texture

The question

Currently, I use a Value node which outputs #frame to change the position of the dot along with time of animation, just like a oscilloscope in the real world. The curve

But I'd like to go furthur - I want to show the curve all at once, that is, to show the entire curve in one frame.

Example

A common definition of Lissajous Curve is given as: $$ f(x)=\left\{ \begin{aligned} x & = \sin(\theta) \\ y & = \sin(\omega \theta + \phi) \\ \end{aligned} \right. $$

To display this, I have to input a range of $\theta$ in the Shader Editor. And to the best of my knowledge, this is impossible unless an output node, like the Value, is capable of outputing a "continuous" value range.

Is there any way I can output a value range, or is there any workaround? Thanks a lot!

$\endgroup$
5
  • 1
    $\begingroup$ Instead of #frame use a repeat zone and set the iterations as high as you need. $\endgroup$ Commented Oct 16 at 13:38
  • $\begingroup$ Thank you very much for your reply! Sorry, I'm new here. I can't find a repeat zone in the Shader Editor. After some search, I unterstand that the repeat zone is a feature in the Geometry Editor, which I'm very unfamiliar with. Do you mean that I'll have to draw my plot using the Geomery Editor instead? Thank you! $\endgroup$
    – Mike Liu
    Commented Oct 16 at 14:12
  • $\begingroup$ Forget what I said, I'm an idiot and I have old bad eyes. On my phone I thought I saw the Geometry Nodes Editor. 🤦‍♂️ Or actually I modtly looked at the nodetree under "The Question", which basically contains mostly Math nodes that exist in Geometry Nodes as well. $\endgroup$ Commented Oct 16 at 15:12
  • $\begingroup$ Thank you for your time! It seems to me that the shader Editor doesn't support iteration or repeat. Maybe I'll have to look into the Geometry Nodes or maybe turn to some Python scripts. $\endgroup$
    – Mike Liu
    Commented Oct 16 at 15:34
  • 2
    $\begingroup$ Lissajous table Pattern in Blender Geometry Nodes $\endgroup$ Commented Oct 16 at 15:35

0

You must log in to answer this question.

Browse other questions tagged .