How can I make object of single mesh to appear from bottom up. I can change alpha of shader to make object appear or disappear or make it semitransparent but how to make it semi transparent partially. For example If I wanted to make a bottle 50% transparent and “fill it” from bottom up with full opacity. So lets say 30% of bottle from bottome will be full opacity and rest with 0.5 alpha.
Is there a way to achieve this?
A possible solution for u may be to use a separate object inside the bottle to act as the fluid. If you set the scale properly when exporting the mesh( in unity y = 1, being full ) then you could just set the scale on the y axis to be the exact percent the user has filled. Setting y to .1 would be 10%. This makes it pretty easy for you, as you wont need to do more complex shader calls/calculations. If there is a reason this will not work for your purposes, please update your question with any additional info.
You can also use a transparent shader with alpha - texture and animate the uv on it.