How to make a water bottle for a game...

NAIMA

that has no complex pbr material system?

So I am wondering how it could be the best approach to make a water bottle for a game, ( secondlife ) to make it look realistic, I modeled thebottle, inside and outside, the cap , water inside, but I have tried to give its transparency , but the liquid inside would disappear because the game only allows one layer of transparency textures with alpha blending and not multiple ones ... The other Idea I had was to eventually fully bake reflections and all into the texture throught rendering it in vray in 3dsmax, but then the transparent and refractiveness wouln't be caught ... so I am a bit puzzled , I know this it may look like a stupid issue but I am finding no solution so far ....

suspectlogic

Not a stupid issue. I've never used Havok game engine but the problem could be similar to what you'd encounter in Unity. Layers of transparency can be forced to render more predictably if you separate the materials. So you could make a water material for the mesh inside, and a separate bottle material for the plastic bottle on the outside.

NAIMA

I have made different materials , but they have this annoying flipping color if you look at those from different angles, or totally disappear at certain others, so I was thinking eventually to bake on the model itself a faked texture ... but I dunno how to simulate and render to texture , reflection , environment and pseudo fake transparency ... of course if I could render all that in a non transparent texture that kind of fakes a transparent bottle look I could then add some moderate transparency in the game to fake the illusion ...

problem is how do I render to texture reflection , refraction and transparency in vray or any other rendering engine?

oglu

Or you do it with a shader. 
https://youtu.be/dFv8lM-kS4E

NAIMA

Unfortunately Secondlife engine doesnt allow liquids.

poopipe

Make the liquid opaque and forget about baking any sort of reflection/refraction effects.  These are entirely view angle dependant so will always look shit

Eric Chadwick

In older renderers, the alpha blending is simplistic. I recently wrote a guide for glTF rendering that might help you. It has a few solutions for this issue. 

https://github.com/KhronosGroup/3DC-Asset-Creation/blob/main/asset-creation-guidelines/full-version/sec05_MaterialsAndTextures/MaterialsAndTextures.md#alpha-coverage-errors

NAIMA

thanks I will check .