WebGLRenderer: renderer.info.render data is wrong if use BatchedMesh._multiDraw

[agargaro]

Description

Using BatchedMesh and multiDrawElementsInstancedWEBGL, the triangles and drawcalls in the renderer.info.render are not correct.

Reproduction steps

1. Create a new BatchedMesh
2. Set these multidraw properties (using at least two geometries):

_multiDrawStarts
_multiDrawCounts
_multiDrawInstances
_multiDrawCount

3. Check renderer.info.render

Code

this._multiDrawStarts = multiDrawStarts;
this._multiDrawCounts = multiDrawCounts;
this._multiDrawInstances = multiDrawInstances;
this._multiDrawCount = range.length - 1;

Live example

In this example I use multidraw to manage the LODs of an InstancedMesh with a single drawcall

https://stackblitz.com/edit/three-ezinstancedthree-js-bug-drawcall-triangles-infomes?file=src%2Fmain.ts

Screenshots

Here there should be one draw call and fewer triangles

Version

r169

Device

No response

Browser

No response

OS

No response

[CodyJasonBennett]

Thanks! Was looking into a fix since seeing #29488 and noticing the count was wrong here.