Disable matrix optimizations

[johnshaughnessy]

Is your feature request related to a problem? Please describe. Our matrix optimizations are a frequent source of confusion. I would find it helpful in debugging to be able to fall back to the default THREE.js behavior or even some "slow and dumb" contract whereby setting any of an object3D's position, rotation, quaternion, scale, matrix, worldMatrix, or parent will cause the reset of the properties to update.

Describe the solution you'd like An easy way to disable our matrix optimizations for debugging purposes.

┆Issue is synchronized with this Jira Task

[johnshaughnessy]

TODO:

• Fix incorrect use of matrixIsModified in track-pose
• Add parent.updateMatrices() to our overwrriten lookAt

[imskr]

I want to work on this issue @johnshaughnessy Please assign!

[gfodor]

Just FYI, I did extensive benchmarking when I wrote these optimizations, and they are relatively huge wins performance wise. I can dig up the numbers if you want.

On Sat, Jan 11, 2020 at 12:04 AM Shubham Kumar notifications@github.com wrote:

I want to work on this issue @johnshaughnessy https://github.com/johnshaughnessy Please assign!

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[gfodor]

Also I did not use the profiler to measure this, but did a series of real world benchmarking

On Sat, Jan 11, 2020 at 1:01 PM Greg Fodor gfodor@gmail.com wrote:

Just FYI, I did extensive benchmarking when I wrote these optimizations, and they are relatively huge wins performance wise. I can dig up the numbers if you want.

On Sat, Jan 11, 2020 at 12:04 AM Shubham Kumar notifications@github.com wrote:

I want to work on this issue @johnshaughnessy https://github.com/johnshaughnessy Please assign!

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[gfodor]

Also, the multiplication isn’t really the issue, it’s the high number of functional calls and all the conditional branching. Even slightly changing the control flow (eg not short circuiting recursion well, or stepping into a branch unnecessarily) often yielded measurable consequences given how much these routines are hit.

[joshmarinacci]

What was the resolution on this? @fernandojsg @netpro2k