Experimental CADS implementation for ComfyUI
Attempts to implement CADS for ComfyUI.
Credit also to the A1111 implementation that I used as a reference.
Usage
Apply the node to a model and set noise_scale > 0.0.
The node sets a unet wrapper function, but attempts to preserve any existing wrappers, so apply it after other nodes that set a unet wrapper function, and it might still work.
t1 and t2 affect the scaling of the added noise; after t1, the noise scales down until t2, after which no noise is added anymore and the unnoised prompt is used
start_step and total_steps are optional values that affect how the noise scaling schedule is calculated. If start_step is greater or equal to total_steps, the algorithm uses the sampler's timestep value instead which is not necessarily linear as it's affected by the sampler scheduler.
The rescale parameter applies optional normalization to the noised conditioning. It's disabled at 0.
apply_to allows you to apply the noise selectively.
Bugs
The implementation might not be correct at all; I'm not 100% clear on the math as to where the noise is actually supposed to be added. and I couldn't make it produce quite the same results as the A1111 node. The algorithm still seems to help with variety though.
Not tested with SDXL. Might do weird things.
I'm not sure if the rescale parameter does anything useful, but feel free to experiment.