One room. Three hard caps.
You are shipping a furniture placement app. A customer points their phone at their living room and your scene has to appear, and hold 60fps, on a mid-range Android.
The draw call rule for this exercise:
One draw call per material on a placed object. A model with eighteen materials costs eighteen draw calls, however few triangles it has. Real engines batch and instance, so this is an approximation, but it is the right mental model and it is the number that actually breaks phone AR.
Your budgets
Triangles (tris)100kWhat the GPU has to transform. Budgets are always quoted in tris
Draw calls50How many times the CPU interrupts the GPU
Texture memory60 MBWhat has to fit in VRAM before anything draws
The scene has to contain
Most assets come in more than one version.
You can only place one version of any given object. Choosing the cheaper version is not cheating, it is the entire job. Every variant tells you what you give up.
Triangles (tris)0 / 100k
Draw calls0 / 50
Texture memory0 / 60 MB
Available assets
one version per objectPlace the required items first.
—Last step
Which lever did you pull, and what did you give up?
Your scene fits. Anyone can get there by deleting things. What matters is knowing what it cost you.
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