Week 4 - Finalizing glTF loader#

What did you do this week?#

This week I had to travel back to my college since the summer vacations have ended. I had a coding session with Serge this week, we modified the exporter function and looked at some bugs I faced.

We managed to use the io.load_io function. There was a strange issue with loading png files. I had to convert the PIL Image to RGB format, and it fixed the issue, turns out png images are stored as P (pallet) mode.

I also added the glb format support to the importer. While loading a .glb model, I noticed that the image data is also stored in the buffer and there can be a bufferview index to get the buffer.

During this time, I also tested the glTF loader with all models in the KhronoosGroup/glTF-samples repository. Here’s the table of models working well: see file.

Model Name

Status

Error Type

BoxInterleaved

No

“BoxInterleaved.gltf: shapes (4,4) and (7,12) not aligned: 4 (dim 1) != 7 (dim 0)”

Box

Yes

SpecularTest

Yes

AnimatedCube

Yes

NormalTangentMirrorTest

Yes

AnimatedTriangle

Yes

SpecGlossVsMetalRough

No

SpecGlossVsMetalRough.gltf: ‘NoneType’ object has no attribute ‘baseColorTexture’

CesiumMilkTruck

Yes

VC

Yes

WaterBottle

Yes

AnimatedMorphCube

Yes

Sponza

Yes

SciFiHelmet

No

SciFiHelmet.gltf: Python int too large to convert to C long

Triangle

No

None: file not downloaded

IridescenceMetallicSpheres

No

None: file not downloaded

Corset

Yes

Cube

Yes

TextureLinearInterpolationTest

Yes

SimpleMeshes

Yes

Lantern

Yes

TextureTransformMultiTest

Yes

TextureSettingsTest

Yes

LightsPunctualLamp

Yes

DamagedHelmet

Yes

CesiumMan

Yes

Cameras

Yes

BarramundiFish

Yes

MetalRoughSpheresNoTextures

Yes

EnvironmentTest

No

None: file not downloaded

MosquitoInAmber

No

MosquitoInAmber.gltf: buffer is smaller than requested size

BoxTexturedNonPowerOfTwo

Yes

BrainStem

Yes

SimpleMorph

Yes

OrientationTest

Yes

BoxAnimated

Yes

StainedGlassLamp

Yes

TextureTransformTest

No

None: file not downloaded

ClearCoatTest

Yes

IridescenceLamp

No

None: file not downloaded

DragonAttenuation

No

DragonAttenuation.gltf: buffer is smaller than requested size

RecursiveSkeletons

No

RecursiveSkeletons.gltf: cannot reshape array of size 120 into shape (9)

Suzanne

Yes

RiggedSimple

Yes

TextureEncodingTest

Yes

2CylinderEngine

Yes

NormalTangentTest

Yes

MorphStressTest

Yes

IridescenceDielectricSpheres

No

None: file not downloaded

TextureCoordinateTest

Yes

Duck

Yes

AlphaBlendModeTest

Yes

TriangleWithoutIndices

Yes

MultiUVTest

Yes

BoomBoxWithAxes

Yes

Box With Spaces

No

Box%20With%20Spaces.gltf: ‘NoneType’ object has no attribute ‘shape’

SheenCloth

Yes

ToyCar

No

None: file not downloaded

MaterialsVariantsShoe

No

MaterialsVariantsShoe.gltf: buffer is smaller than requested size

IridescentDishWithOlives

Yes

VertexColorTest

Yes

SheenChair

Yes

Fox

Yes

AntiqueCamera

Yes

TransmissionTest

No

None: file not downloaded

TransmissionRoughnessTest

Yes

BoxVertexColors

Yes

ReciprocatingSaw

Yes

MorphPrimitivesTest

Yes

MetalRoughSpheres

Yes

GearboxAssy

Yes

TwoSidedPlane

Yes

Buggy

Yes

SimpleSparseAccessor

Yes

BoxTextured

Yes

UnlitTest

Yes

SimpleSkin

Yes

FlightHelmet

Yes

Unicode❤♻Test

No

Unicode%E2%9D%A4%E2%99%BBTest.gltf: ‘NoneType’ object has no attribute ‘shape’

Avocado

Yes

InterpolationTest

Yes

GlamVelvetSofa

Yes

RiggedFigure

Yes

BoomBox

Yes

EmissiveStrengthTest

No

None: file not downloaded

AttenuationTest

Yes

AnimatedMorphSphere

Yes

IridescenceSuzanne

Yes

What is coming up next week?#

  • Adding tests and merging export function PR.

  • Start working on Simple Animations.

Did you get stuck anywhere?#

  • To create a texture, we needed the RGB values, However .png images were returning a 2D array when read using PIL. It is fixed by

    if pil_image.mode in ['P']:
       pil_image = pil_image.convert('RGB')
    
  • pygltflib’s load method doesnot handle glb files very well. It does not contain the buffer uri. I used glb2gltf method as of now.