EXRLoader: Cannot read properties of undefined (reading 'width' )

[mrdoob]

They load fine in GIMP. The one I referenced earlier is mostly white is maybe less useful for demonstration purposes, but here's another that won't load for me in THREE.js but loads fine in GIMP.

You can download the 2K zip here, then try loading rebar_reinforced_concrete_rough_2k.exr in THREE.js and it should repro TypeError: Cannot read properties of undefined (reading 'width') in THREE 176 as outlined above.

Originally posted by @drone1 in #10652

[WestLangley]

MacOS is unable to open the referenced file for me.

[drone1]

GIMP or THREE?

…

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[WestLangley]

MacOS Preview.app cannot open it, but MacOS blender.app can.

[drone1]

Okay.

Here's my original post, for reference:

Hi all,

I'm having some trouble loading some .exr files (in THREE v176) downloaded from Polyhaven and I'm wondering if it's an error in the files or a bug in the code. Some .exr files from the site work just fine, and others fail with the same error:

TypeError: Cannot read properties of undefined (reading 'width')

I dug a tiny bit and things fail in lossyDctDecode:

function lossyDctDecode( cscSet, rowPtrs, channelData, acBuffer, dcBuffer, outBuffer ) {

	let dataView = new DataView( outBuffer.buffer );

	const width = channelData[ cscSet.idx[ 0 ] ].width;

cscSet.idx is an Array(3) but is empty, thus referencing index 0 here throws an exception.

It looks like cscSet.idx[0] is never set because the channel rule's index for channel with name Y is -1, and thus this code is never run:

if ( rule.index >= 0 ) {

	cscSet.idx[ rule.index ] = offset;

}

Here's the file I'm working with: Download (free, no signup) the 1K zip on Polyhaven and check (concrete_block_wall_02_rough_1k.exr).

If this is indeed an error in the data, perhaps the loader could be adjusted to be resiliant in this case? I'd say about 1/3-1/2 of the ~50 Polyhaven materials I downloaded have .exr's that don't work with EXRLoader.

Otherwise it's working great! Thanks for the great work.

[sciecode]

I'm currently unable to tackle this issue. I was, however, able to confirm the current DWAA/B decompressor is incomplete. There are 2 missing components that would need to be implemented.

The 3-Channel RGB LossyDctDecode is assumed to be universal to every DWA compressed file, this is an incorrect assumption.

three.js/examples/jsm/loaders/EXRLoader.js

Line 1638 in e5a695b

lossyDctDecode( cscSet, rowOffsets, channelData, acBuffer, dcBuffer, outBuffer );

Only when the input file has 3 channels with matching compression information, this should be executed, and solely on those channels.

For the channels that don't get decoded in the previous step, they are required to be individually decoded, either by RLE (which is supported and implemented), or by the single-channel LossyDctDecode which hasn't been implemented. (the file provided requires this exact scheme)

three.js/examples/jsm/loaders/EXRLoader.js

Line 1676 in e5a695b

case LOSSY_DCT: // skip

For anyone willing to add support to both of these features, the original OpenEXR implementation can be found here: AcademySoftwareFoundation/openexr/DwaCompressor_uncompress

Most of our current implementation was pulled from this exact version, so there is substantial similarities in implementation & variable naming. Which should make this easier.

In case anyone chooses to make a PR addressing these, feel free to reach out to me for any pressing issues, I'll try to get back to you as soon as possible.

[mrdoob]

@drone1

If this is indeed an error in the data, perhaps the loader could be adjusted to be resiliant in this case? I'd say about 1/3-1/2 of the ~50 Polyhaven materials I downloaded have .exr's that don't work with EXRLoader.

Do all show the same error?

[drone1]

@drone1

If this is indeed an error in the data, perhaps the loader could be adjusted to be resiliant in this case? I'd say about 1/3-1/2 of the ~50 Polyhaven materials I downloaded have .exr's that don't work with EXRLoader.

Do all show the same error?

Yes.