How do you approach (impossible) GLASS baking?

Hey all.
Let’s say you model a room and want to bake textures to bring into a game engine.
Now let’s say you have a window in that room.

Given that you can’t ‘bake’ transparency really, what is the approach? Do you leave the surface with no material and apply some glass material in a game engine?

Suggestions appreciated.

The question is: what can you bake on glass?

Game engine’s generally aren’t very good at transparency, and most have no concept of refraction/reflection etc. As a result, pretty much the only thing you can bake about glass are the non-transparent parts.
Real glass is not quite transparent. It has dust, scratches etc. that influence the lighting. If you’ve modeled this into your blender shader, you may be able to extract useful information from baking lighting.

Thanks for the replies, guys!

So would I follow both of your suggestions combined: small dust / scratches on an alpha channel, to give the illusion of some subtle texture on transparency?

Alpha in a nutshell: white is opaque, black is invisible, shades of grey represent the in-betweens.
So, for instance, you could bake out an alpha map where only dust and scratches are white, then leave the rest semi transparent.

However to get more refined effects, like slightly adjusting transparency depending on camera angle or light direction and instensity, you’d still need to work on a shader within the game engine. What baking gives you is color information for such a shader to work with, so more sophisticated effects can be achieved.

you can bake reflection probes in blender internal - or update them dynamically in upbge,

we really need a reflection buffer that a piece of it is reserved for each object, and use a GLSL script to udpate the buffers (parralax corrected cubemaps)

this will be use until SSR, even then it’s a fallback from SSR.