Invert Image

Invert Image is a pass-through filter node: it takes an image on its Image input port, renders one fullscreen triangle over the upstream texture, and writes the result to its own offscreen texture, which it exposes on its Image output. Nothing is composited to screen here — the output still needs a Canvas node.

Because Grafit generator textures are stored premultiplied, a naïve 1 − rgb would brighten transparent regions into grey haze. The shader therefore does the mathematically correct thing per pixel:

1. Un-premultiply — rgb = a > 0.001 ? rgb / a : 0
2. Invert and blend — outRGB = mix(rgb, 1 − rgb, Amount)
3. Alpha — a = Invert Alpha ? mix(a, 1 − a, Amount) : a
4. Re-premultiply — the returned color is float4(outRGB × a, a)

So with Invert Alpha off, transparent pixels stay perfectly transparent and only visible color is negated. With Invert Alpha on, the coverage itself is inverted — what was solid becomes empty and what was empty becomes solid — which turns any shape into its own inverted stencil.

Amount is clamped to 0…1 and interpolates linearly:

The node is flagged as always-dynamic and it keeps its source rendered even when that source isn't on a Canvas of its own — so you can chain a generator straight into Invert Image without also having to composite the original, and live inputs (camera, video, fluid sims) update every frame.

The Width and Height outputs pass the upstream generator's dimensions straight through (falling back to 2.0 × 2.0 if nothing is connected), so the filter is transparent to any downstream node that needs the source's footprint. When Enable is false, or when no image source is connected, no pass is drawn and the output texture is left cleared.

Interactions: Amount drives both the color and the alpha inversion, so with Invert Alpha on, a mid Amount gives a half-solid, half-transparent wash rather than a clean stencil — use Amount at 1.0 when you want a crisp inverted mask.

• Beat-synced negative flash — Audio Beat Detection → Amount for a strobing full-frame inversion on every kick.
• Breathing color reversal — LFO (0…1) → Amount across a slow cycle so a video or camera feed melts in and out of negative.
• Live camera negative — Camera Input → Invert Image → Canvas for an instant X-ray/darkroom look on a performer.
• Inverted stencil from a shape — Circle 2D → Invert Image with Invert Alpha on and Amount 1.0, then feed the result into a Canvas node's Mask input to punch a hole instead of cutting a disc.
• Negative text over footage — Text as Image → Invert Image → Canvas on a layer above Video Player, so type reads against any background.
• Fluid contrast pass — Liquid Simulation → Invert Image → Gaussian Blur → Canvas (additive blend) for glowing inverse plumes.
• EEG-driven mood switch — FFT EEG band power → Remap (0…1) → Amount so the whole scene inverts as attention or relaxation rises.

• This is a filter, not a source: it needs both an upstream image on its Image input and a downstream Canvas node to be seen.
• The upstream generator does not need its own Canvas — Invert Image keeps its source rendered off-canvas automatically.
• Inversion is premultiplied-correct: leave Invert Alpha off and transparent regions stay clean, with no grey halo around antialiased edges.
• Amount at 0 still costs one fullscreen pass; use Enable (or bypass the node) when you want a genuinely free pass-through.
• It is a single cheap fullscreen pass, so it stacks freely with other image filters — chain it with Image Adjustment, Gaussian Blur, Image Transform, Mask Grow, or Mask Outline in any order (order changes the look).
• The Width/Height outputs mirror the source, so a Canvas node sized from this filter matches a Canvas sized from the original.