Batch Rendering = Head Spin
polycounter lvl 11
I'm a little confused at the moment, I want to understand how batch rendering works in most engines so that I can integrate it into my thought process and pre-planning for modular environments.
If I have two buildings that each share the same 4 textures but that each have a unique overlay texture (AO Map, and Details in a second UV set) does that mean that these two buildings will not be batch rendered together?
In other words these buildings could share the exact same materials but all 4 materials (roof, walls, floor) have an AO texture that is unique to each house and I really don't get how that effects the batch rendering process.
I am also wondering if this is something that can even be generalized to the point where we can deal with it in general terms or if each engine handles batch rendering so differently that you need to be talking to your programmers about it.
Edit: Here is a pic further explaining my confusion. My confusion started after reading this, I don't really understand what ultimately determines a render pass or batch, if someone could sum it up for me I would greatly appreciate it.
If I have two buildings that each share the same 4 textures but that each have a unique overlay texture (AO Map, and Details in a second UV set) does that mean that these two buildings will not be batch rendered together?
In other words these buildings could share the exact same materials but all 4 materials (roof, walls, floor) have an AO texture that is unique to each house and I really don't get how that effects the batch rendering process.
I am also wondering if this is something that can even be generalized to the point where we can deal with it in general terms or if each engine handles batch rendering so differently that you need to be talking to your programmers about it.
Edit: Here is a pic further explaining my confusion. My confusion started after reading this, I don't really understand what ultimately determines a render pass or batch, if someone could sum it up for me I would greatly appreciate it.
Replies
However you could pack those AO maps into a single big AO map, and then use the same material on each house, just offsetting the UVs to match. That would batch all as one.
However... your engine has to be written to support batching in the first place. Talking to your rendering/graphics programmer is a good habit to get into in general. I've learned so much from the ones I've worked with.