Original Post
Our renderer here at work does not currently support geometry instancing. We have a separate draw call for all of the models in the scene even if they are exactly the same. I wanted to switch over to using geometry instancing and I'm trying to investigate a little.
Would there be a cost to always do rendering with geometry instancing? Most of our models are unique in the scene so if the system always used the geometry instancing mechanism then most of the time it would only draw one instance. But the way I see it, there is no extra cost other than having to use two vertex streams. Would it be unwise to just always render with geometry instancing on? Maybe the vertex processer incurs more of a hit when fetching per instance data from different stream than the geometry. Will this cause more vertex cache misses?
Would there be a cost to always do rendering with geometry instancing? Most of our models are unique in the scene so if the system always used the geometry instancing mechanism then most of the time it would only draw one instance. But the way I see it, there is no extra cost other than having to use two vertex streams. Would it be unwise to just always render with geometry instancing on? Maybe the vertex processer incurs more of a hit when fetching per instance data from different stream than the geometry. Will this cause more vertex cache misses?
