@Subrahmanya_Chakrava the best way to think of how you need to configure your assets for Babylon is to think of them as real time game assets. You can get high quality rendering out of a real-time engine, but you can’t approach the assets as you would if you were ray tracing them.
This breaks down into two main issues when converting from pre-render workflows to real-time render workflows:
- Shadows, including self shadowing
- Global illumination and reflections
For shadows the trade off you need to make is that to get soft shadows that are impacted by bounced light, or global illumination, you will need to bake your shadows into a light map for your object, so you are limiting the object to not moving in the scene and always being in the same position in your scene. You can get soft, real-time shadows but those are more expensive to render at run time and won’t be affected by global illumination as we aren’t calculating any bounces in the lights (which would lead us to real-time ray tracing that requires a lot of compute power). Self shadow is also a more expensive method that is easily solved by baking your lights. You are more performant with a shadow map than with self shadows in real time, but you further lock down the asset as it can’t have animation or the baked shadows become obvious.
A great tutorial for baking light maps in Maya is available at Pluralsight. It is a little older, but the principles are still the same. This is the best way to get soft shadows affected by global illumination.
The other part which is global illumination and reflection is a harder solve in real time. Baking your lights into a shadow map will add the global illumination into the shadow maps, but you still need to account for illumination for a bounce. Consider this image from Unity:
It deals with both of the challenges we face. Objects close to a colored wall will receive color contribution from the global illumination or bounced light. The sphere near the green wall takes on a green cast in its lighting calculation. And the metallic sphere in the center reflects the environment. One of the issues, the reflection, can be solved with reflection probes which bake a local cubemap which is used for reflection. The problem is that you are baking 6 images every frame to account for objects moving which can get expensive very quickly.
And for the environment lighting, you need to provide a precomputed DDS so that we can use the mip levels as a substitute for calculating the specular lobe based on roughness per pixel every frame. I’m currently talking about environment maps in another thread on the forum, so I won’t repeat it all here.
So, if you bake an environment map of the room your scene is set in, you can get both reflection and image based lighting (IBL) out of the one file, but the user cannot interact with things in the scene, i.e. move furniture around or replace it. However this will render the fastest in real time.
If you need to make use of interaction with the objects within your room, you will need to likely make use of two tricks. The first would be to bake out an environment map of your room empty for IBL and then use reflection probes to handle all of the reflections of dynamic objects.
The downside here is that baking shadows across objects is not going to work. You can bake self shadows into an object like a chair, but you won’t be able to bake the shadow into the floor asset. The thing you will need to do is create a plane under the object that catches the shadow and when you assemble the scene, the texture on the shadow catcher uses a multiply blend mode in the material so that it will look like it affects the floor asset.
To get the quality of render you showed as your example, you will never get completely away from baking some textures until our everyday hardware catches up to top of the line GPUs. Until then you can break down the problem in to manageable chunks and will have to use some smoke and mirrors and some trade offs to get the assets to behave the way you want. I will say that this is a very typical workflow for game engines today. And there are a lot of resources available online for creating realistic game assets. If you frame your queries around game assets, you will find everything you need. Let me know if you have more questions.