I’m not sure what you mean with remapping with a texture atlas. Do you have a different texture per step of animation? Do you mean lut?
The reasons why I choose to use smoothstep:
- Animating from 0 to 1 just makes sense to me, you can go into a curve editor inside of cascade and just animate the value there and it will make sense inside that editor as well.
- Smoothstep is an hlsl command.
(Unreal does this thing where every node is a variable defined as a combination of other variables and values. adding nodes therefore adds a certain cost and complexity to your shader.)
So it should in theory be more optimised then combining addition and multiplication to achieve the same result. (Not that addition and multiplication are expensive, but still) - Smoothstep is, well, it’s as smooth function, it doesn’t leave ugly lines and artifacts.
Back to your question,
- Texture atlases are giant and expensive on memory, so I wouldn’t use them in this case.
- Luts are a great idea however if you want colours, they are so much easier to use then having to manualy manage colours.
Thing is, even when I use luts for something like this, I tend to remap my values first, before I feed them into the lut.