Yusuf's Thoughts

Image to POPs (Pointcloud and Line Grid)

4 min read

Inspired by: PPPANIK - IMAGE TO POPs: POINTCLOUD / LINE GRID

This tutorial covers the “Image to POPs” workflow shown by PPPANIK: converting a 2D texture into a 3D point cloud or a structured line grid on the GPU. It suits clean, “holographic” blueprint looks and dense generative visuals.

Operator Families in this Recipe

  • TOPs (Texture Operators): Pre-processing the source image for the GPU.
  • POPs (Point Operators): Converting and manipulating millions of points on the GPU.
  • MATs (Materials): Applying the Line MAT for the classic wireframe/grid aesthetic.

Part 1: Source Preparation (TOPs)

The density of your point cloud is directly tied to the resolution of your source image.

  1. Movie File In TOP: Load your image or video.
  2. Fit TOP:
    • Fit Method → Fit Outside.
    • Common Page > Output Resolution → 200 x 200 (40,000 points) or 500 x 500 (250,000 points).
    • Interpolation → Nearest. This prevents pixel values from blending together during resize, so each point gets a clean, discrete color value.
  3. Level TOP: Increase Contrast to sharpen the distinction between light and dark areas.

Part 2: Pixel-to-Point Conversion (POPs)

  1. Geo COMP: Create a new Geometry component and enter it. Delete the default Torus.
  2. TOP to POP:
    • TOP → Reference your Level TOP.
    • Position Mode → UV or Height.
    • This maps the pixel coordinates (0-1) to 3D space.
  3. Delete POP:
    • Operation → Delete by Expression.
    • Expression → me.inputPoint.color.r < 0.1.
    • This “culls” the background, leaving only the points that represent the bright parts of your image.
  4. Noise POP:
    • Amplitude → 0.15.
    • Transform (Translate Z) → absTime.seconds * 0.1.
    • This adds a subtle, organic ripple to the point cloud.

Part 3: The Line Grid Aesthetic

There are two main ways to achieve the “Grid” look:

Method A: Instancing (Copy POP)

  1. Rectangle POP: Create a very small, thin rectangle.
  2. Copy POP:
    • Input 1: Rectangle POP.
    • Input 2: Your point cloud (from Part 2).
    • Copy Page > Use Template Point Attributes → On.
  3. Line MAT: Apply a Line Material to the Geo COMP with Draw Lines and Draw Points enabled.

Method B: Line Strips (Joining Points)

  1. Join POP: Connect your point cloud to a Join POP.
    • Set the Maximum Join Distance to a small value.
    • This connects neighboring points with line primitives, creating a structured mesh/grid.
  2. Line MAT: Apply a Line Material. Since the Join POP creates actual line primitives, the Line MAT renders them as a wireframe grid.

Part 4: Rendering & Post-Processing (The “Pro” Look)

PPPANIK often finishes with a composite trick:

  1. Render TOP: Standard setup with a Camera and Light.
  2. The Glow (Feedback):
    • Render TOP → Feedback TOP → Blur TOP (Filter Size 2) → Level TOP (Opacity 0.9) → Add TOP.
  3. Softlight Composite (Pro Tip):
    • Create two versions of your render: one clean (Pointcloud) and one with the Line Grid.
    • Composite TOP: Combine both versions.
    • Operation → Softlight.
    • Softlight blends the sharp lines into the soft glow of the point cloud.

Pro Tip: Texture Indexing

If you want to instance thousands of different images onto these points (rather than just drawing lines), you must use Texture Indexing:

  1. Index Creation: Use a Math POP or Attribute POP to create a custom attribute called tex_index.
  2. Expression: Set the value to me.inputPoint.id % [number_of_images].
  3. Geo COMP: In the Instance 2 page, drag your POP into the “Texture Index OP” and set the “Texture Index Attribute” to your tex_index.
  4. Result: Every point in your cloud now displays a unique image from your texture array.

Parameter Tuning & Behavior

ParameterBehavior
TOP ResolutionDirectly controls “resolution” of the 3D form. 500+ requires a strong GPU.
Delete ThresholdHigher = “thinner” form; Lower = more background pixels included.
Join Distance(Method B) Higher = more “messy” connections; Lower = strict grid structure.
Feedback BlurControls the “bloom” and softness of the digital trails.

Network Architecture

[ SOURCE TOPs ]
Movie File In ──▶ Fit ──▶ Level ──▶ [ TOP to POP ]
                                         │
                                         ▼
[ POPs ]                           [ Delete POP ] ──▶ [ Noise POP ]
                                                              │
                                                              ▼
[ MAT ]                            [ Join POP ] ◀─────[ POP NETWORK ]
Line MAT ────────────────────────▶ [ Geo COMP ]
                                         │
                                         ▼
[ RENDERING ]                      [ Render TOP ] ──▶ [ Feedback Loop ]
                                                              │
                                                              ▼
[ POST-EFFECT ]                    [ Composite TOP (Softlight) ] ──▶ OUT

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