Params in "Transforming Material Textures" UE video

[cazgamedev]

How does UE automatically know that “U Texture scale” and “V Texture scale” are to be mapped to U and V params when we append it?

I’m just confused how I would go about mapping other parameters in the future. It just seemed that by placing that it automatically knows to map it to UV but what if I want to expose other parameters, how would I tell it to expose a certain parameter in this instance?

[DanM]

It doesn’t “know” what to multiply by what.

• The texture coordinate is a 2D vector storing U and V
• You created parameters UScale and VScale (I forgot the names Mike used)
• You then used Append which turns it into a 2D vector so you now have [UScale, VScale]
• Multiplying is done component-wise the first are multiplied together and then the second.

If you switched the order of the Append node then the UScale would apply to the V channel.