Separate Model and View Matrices.

[deveshidwivedi]

Resolves #5287

Changes:

Introduced a distinct modelMatrix. By separating these matrices (modelViewMatrix), it would become easier to manipulate each aspect of the transformation independently, allowing for more flexibility especially when working with shaders.

PR Checklist

• npm run lint passes
• Inline documentation is included / updated
• Unit tests are included / updated

[davepagurek]

Great work on this so far! I left some comments where it seems like the behaviour we had before wouldn't be completely the same afterwards -- normally when we reset uMVMatrix to just the camera matrix in the past, now that means we have to reset the model matrix and set the view matrix to the camera matrix.

[davepagurek]

Looks like tests are failing because:

It seems like it's because of this line still setting uMVMatrix rather than the model and view matrices:

p5.js/src/webgl/p5.Camera.js

Lines 1393 to 1395 in 2ceca4e

	if (this._isActive()) {
	this._renderer.uMVMatrix.set(this.cameraMatrix);
	}

Might be worth searching in the repo for this.uMVMatrix or _renderer.uMVMatrix to make sure we aren't leaving any other lingering references to it

[deveshidwivedi]

@davepagurek I made a few changes, please let me know if they make sense..
I rechecked files to see where I missed initialization but couldn't really make any improvements..
I had a doubt, do we need to introduce or update any camera properties specifically to get things working?

[davepagurek]

Looks like tests are still failing because it still tries to set uMVMatrix here too:

p5.js/src/webgl/p5.Camera.js

Line 1394 in f5baf36

this._renderer.uMVMatrix.set(this.cameraMatrix);

Maybe try searching this file to make sure it doesn't reference uMVMatrix anywhere any more?

I had a doubt, do we need to introduce or update any camera properties specifically to get things working?

I think the camera matrices are OK as is! I think your code is making the right changes already, so it's just a matter of finding any bits that we missed where we need to apply the same pattern.

[davepagurek]

Looks like now, the test failures might be at least in part because the tests need to be updated too. e.g. here, the test makes assertions on uMVMatrix, which no longer exists, so we'll probably need to look through the tests and replace these with assertions on uModelMatrix and uViewMatrix:

p5.js/test/unit/webgl/p5.Camera.js

Lines 393 to 396 in faf5252

	assert.deepEqual(
	copyCam.cameraMatrix.mat4,
	myp5._renderer.uMVMatrix.mat4
	);

I also see some other tests failing that probably shouldn't fail. A buildGeometry test is trying to assert that the output looks the same when you draw a model directly to the canvas as if you first save it to geometry, and then draw it to the canvas with model. It's receiving the left image as output, but expecting the right:

so it looks like maybe something about the camera isn't being reset correctly after buildGeometry. I left some comments, but I think we're accidentally taking the camera into account in buildGeometry right now, hopefully that error goes away after editing that one bit!

[deveshidwivedi]

Made these changes, please have a look..

[deveshidwivedi]

Hi @davepagurek! I tried updating a few other tests, please take a look

[davepagurek]

Thanks for your continued work on this! I noticed a few more things that might be throwing the tests off, let's see if those changes get the tests passing.

[deveshidwivedi]

Should we update the matrix here also?

[davepagurek]

I think we're almost done! We only have a few tests still failing, and I think the suggestions I've left will hopefully be enough to resolve them.

[davepagurek]

Should we update the matrix here also?

Ah yes good catch, I think so!

[deveshidwivedi]

Hi @davepagurek! Sorry for the delay. I have made these changes and the tests do no fail anymore. Are any more updates required?

[davepagurek]

Sorry for the delay! I think it's looking good now. We're just finishing up the p5.js website redesign (the source of the delays in my reviews 😅) and will probably be doing another quick release just to push out more documentation updates. After that, we'll be back in a more normal release schedule, including a beta release to do further testing in case we've missed anything from the tests. So I'll merge this in after that little release!

[deveshidwivedi]

Sure @davepagurek! Looking forward!🎉

[Qianqianye]

Thank you all. @davepagurek, are we good to merge this?

[davepagurek]

good to go if we've done our last docs deploy!

[Qianqianye]

Just to clarify, do you mean the updating all the reference doc? @davepagurek

[davepagurek]

right, mostly we were just waiting to put this into a release where we would be able to have a standard beta testing period to catch any bugs. if we're going to be back into a regular release cadence again then this is good to merge!

[davepagurek]

@all-contributors please add @deveshidwivedi for code

[allcontributors]

@davepagurek

@deveshidwivedi already contributed before to code