RemapInsideParabolas

Here's the niche-of-a-niche node in the Remap family, and it's honestly clever. You draw two parabola curves on a mask, and this node remaps your source image so that a straight horizontal band bends to follow the curves - like wrapping a flat strip of labels or text around the curved surface of a bottle or a sign. The mask defines the destination shape; the image conforms to it.

It's a REMAP generator, same as every node in this family: RemapInsideParabolas → Remap → image. The twist is where it gets its geometry - not from sliders, but from a mask you supply.

How it works

You provide a dst_mask_with_2_parabolas: a mask with two drawn curves (the two "edges" of the band you want the image to conform to). The node fits parabolas to those curves and computes a coordinate mapping that stretches a straight band of the source so it lies between the two curves, following their curvature. Think of it as: top edge of the image maps to the first parabola, bottom edge maps to the second, and everything between interpolates - with the arc-length along the curve respected so the image doesn't bunch up on one side.

The single input is the mask, which means your curve-drawing quality is the whole quality of the result. A mask with clean, well-separated parabolas gives a clean warp; a noisy or hand-scrawled mask gives a mess.

The inputs and output

• dst_mask_with_2_parabolas (MASK) - the two curves defining the band's shape.

Output: REMAP.

There's exactly one input, which makes this the simplest node to describe and one of the hardest to drive well in the whole pack. The output dimensions match the mask, which is also what the Remap node will use.

Where you'd actually use it

Bending text or a label onto a curved surface is the textbook case - and because the pack pairs this with text-rendering utilities and compositing nodes, you can genuinely wrap generated text around a cylinder-shaped object. It's also the building block the pack uses for "inside" cylinder effects done with curves instead of a 3D projection. The sibling, RemapFromInsideParabolas, does the exact reverse (unwrap a curved band into a flat rectangle); this one is the wrap-in direction.

Installing it

cd ComfyUI/custom_nodes
git clone https://github.com/bmad4ever/comfyui_bmad_nodes

restart, or search comfyui_bmad_nodes in ComfyUI Manager. OpenCV covers the mechanics; no model downloads.

The honest caveat

The mask-drawn interface is the whole difficulty. Your parabolas need to be recognizably parabolic - two clean, roughly parallel curves - and the node's fitting will follow whatever you drew. Also note this is the simple version: if the warp comes out twisted, RemapInsideParabolasAdvanced is right there with curve_wise_adjust and ortho_wise_adjust knobs to fix exactly those problems. Start here to see the concept working, then switch to Advanced when the curve fit isn't cooperating.