Dynamic Batching + VertexLit + PointLight = 1 Draw call?

[MCHammond]

Scenario:
I have a script that adds and positions hundreds of prefabs, the prefabs are just geometry. The Prefabs are all less than 20 polygons and all have the same shader/materiel “the stock Transparent/Cutout/Vertexlit”.

On daylight scenes that use only directional lights the scene is batched and I only have 2 or 3 draw calls for the geometry.

But on inside scenes like caves were I use a single point light to light each void in the cave system, the scene is not batched.

Question
Why does using point lights stop batching? I assume it is because the shader is using multiple passes to render the lights. but I thought that VertexLit shaders only used one pass? Is there a shader that will use a single pass to render point lights?

Thank you.

[Julien-Lynge]

One possible reason, in the words of Aras:

Q: Does the transparent Queue have different rules for batching?

A: It doesn’t have any effect on batching per se, but indirectly might affect it. Transparent render queues essentially mean “please draw these objects in furthest-to-closest order” (regular opaque queues mean “draw them in any order you like”).

So the transparent objects will be sorted back-to-front and drawn in that order. If sequences of them within that order can be batched, they will be batched. If they can’t, they won’t.