How can i use the image as colormap for my material?

Helllo everyone, i’m trying to make a circle lines with a specific colormap. The reason is need is that creating an iridescent material. I can achieve same result with ColorRamp + LayerWeight (Facing) but my texture has some grey areas.

Here’s the colormap i work with. Any suggestion is welcome.

Edit: I’m sorry, I misread and I totally misunderstood the question.

Not useful answer

Hey blendeR37,

you can map the image like a color ramp by using the output of the Layer Weight node and use it as the x-coordinate with Combine XYZ. Take that vector as the input vector for your image to recreate the effect of the ColorRamp in your screenshot with your image.

Adjusting the y-value in the Combine XYZ node let’s you choose which row of pixels from your Image is used for the effect (0 will give you the bottom greyish gradient, while 1 will give you the saturated top row).

Alternatively you can also use the node setup in the top left to create a circular gradient with a more linear falloff that doesn’t shift with the point of view. Just use the Length output for the x-coordinate rather than the Facing value.

Did you try the different modes of the ramp? Have you tried remapping the facing output into something usable for the wavelength node?