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I have material with emission, but when I set emission to 500, light shows, but texture becomes white. I want to keep texture same and add light from emission. How can I make this?

I have this:1

But I want this: enter image description here

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For the material, you will have to use the Light Path Node and use the Is Camera Output to us as an input for the mix shader node. This mix shader node will basically have 2 emmision shaders plugged into it. Both the emmision shaders will have the same image texture as their input. The strength of one that's plugged above will be what is actually cast into the scene. The strenght of the second one will be what is seen by the camera.

enter image description here

Now since the output rendered image does not have pixels which are bright for that emmisive part we cannot use the glare node directly. So somehow we will need to get where the emmisive part is and use glare on that specific part.

For this we can use cryptomatte!

We can simply use the Material Cryptomatte Pass for this purpose. (Enable them in the View Layer Properties) enter image description here

Now in the Compositor Node Editor, use the Cryptomatte Node and click the plus icon. (Open a image editor on the side) Now hover over the emmisive material part in the rendered image and click. (Or simply just type the name of the Material in the blank space)

Now put a Brigtness Contrast node to increase the brightness.(Otherwise the glare won't be strong enough) Now add the Glare Node set to Fog Glow (Make sure that you have set the Mix value to 1). Multiply this by the inverted mask of the cryptomatte (Otherwise the entire area will be white)

Now Combine the originial with this glare.(Use the Add Blending Mode) enter image description here enter image description here

Now for some reason, the glare in the Compositor has a size limit. So it won't be as big as Eevee's Bloom. But in your case, this is probably the only way possible.

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I don't know if it is possible to get the emission without the surface emitting the light too, but you can fake it.

  • In edit mode, duplicate the emitting faces and separate them.

  • Go back to object mode and select the separated mesh. This will now have the same emitting material.

  • Make a single user copy of the material and reduce the Emission Strength (this way you can add some slight emission to the surface to let it look better imo). But you could also use another material.

  • In the Object panel of the new mesh, go to Visibility > Ray Visibility and turn Shadow off.

  • To avoid z-Fighting and visible emission borders from the underlying original mesh, move the separated geometry as little as possible (like +-0.00001) in the direction of the face normals.

enter image description here

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  • $\begingroup$ It's work, but I want not to light surface, but have the aura(?) imgur.com/5iC1OJQ $\endgroup$
    – Flam3y
    Jul 30, 2023 at 0:22
  • $\begingroup$ Ah ok, misunderstood your question. See the other answers then. $\endgroup$
    – taiyo
    Jul 30, 2023 at 8:32

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