📈 Linear Curve

Every animation eventually needs the same move: start at one value, end at another, don't do anything clever in between. Linear Curve [Dream] is that move, packaged as a node. It takes an initial_value and a final_value, and over the full length of your animation it slides a float from one to the other. A slow zoom from 1.0 to 1.2 across the whole clip. A prompt weight that fades a phrase out while another fades in. A brightness that climbs from "murky" to "washed out" by the last frame. No oscillation, no events, just a steady hand on the dial.

This is one of the core curves in Dream Project Animation Nodes, the pack the "Alt Key Project" music channel built for Deforum-style frame-by-frame animation in ComfyUI. The mechanism is the simplest of the whole family: the node reads your frame counter's progress (a 0-to-1 number that says how far through the animation you are) and computes initial + progress * (final - initial). Because it's driven by progress rather than raw time, the curve always spans the entire animation no matter how long it is - which is the key difference from the periodic curves in the same pack.

The inputs that matter

• frame_counter - required. Feed it any Dream frame counter (Frame Counter (Simple) or Frame Counter (Directory)); the node needs to know both the current frame and total length.
• initial_value - where the output starts (default 0).
• final_value - where the output ends (default 100, so the defaults alone give you a nice 0→100 sweep).

That's the whole input list. Outputs are FLOAT and INT, same value with one rounded - FLOAT for continuous parameters, INT for anything that demands a whole number.

Installing it

The pack installs via ComfyUI Manager - search "Dream Project Animation Nodes" - or by hand:

cd ComfyUI/custom_nodes
git clone https://github.com/alt-key-project/comfyui-dream-project.git
cd comfyui-dream-project
pip install -r requirements.txt

Restart ComfyUI afterward. Requirements are light, though the numpy<2.0 pin is worth knowing about if pip reshuffles your environment.

Common issues

The usual failure is a missing frame counter - the curve has no sense of "how far along" without a FRAME_COUNTER input, and ComfyUI's built-in nodes won't supply one. Use the pack's own counter nodes upstream. One honest caveat about the pack: the README announces it's no longer being updated (the author moved to comfyui-dream-video-batches), but a linear interpolation is about as stable as custom-node code gets, so it runs fine on current ComfyUI. If you want the same ramp but looping forever instead of once across the clip, that's the pack's Saw Curve.