Quill to GLTF Bug

[donmccurdy]

I’m not too familiar with Quill, but I guess the intention for this animation is to cycle through each of the meshes, one frame at a time? The animation data included seems incorrect to me, and I’m not sure how to easily fix that within tools like Blender or Maya. If you know the naming pattern of the meshes (House_# in this case), it might be easier just to script a new animation into the file. For example:

const fs = require('fs');
const path = require('path');
const { NodeIO, FileUtils } = require('@gltf-transform/core');

const FPS = 10;
const INPUT_PATH = 'scene.gltf';
const OUTPUT_PATH = 'scene_step.glb';
const MESH_PATTERN = /House_\d+$/;

const io = new NodeIO(fs, path);
const doc = io.read(INPUT_PATH);
const root = doc.getRoot();

// Remove original animation data.
root.listAnimations().forEach((anim) => {
    anim.listChannels().forEach((channel) => channel.dispose());
    anim.listSamplers().forEach((sampler) => sampler.dispose());
    anim.dispose();
});
root.listAccessors().forEach((accessor) => {
    if (accessor.listParents().length === 1) {
        accessor.dispose();
    }
});

// Collect house nodes.
const houseNodes = root.listNodes()
    .filter((node) => node.getName().match(MESH_PATTERN));

// Create animation cycling visibility of each mesh.
const anim = doc.createAnimation();
const animBuffer = root.listBuffers()[0]
    .setURI(FileUtils.basename(OUTPUT_PATH) + '.bin');
houseNodes.forEach((node, i) => {
    // Create keyframe tracks that show each mesh for a single frame.
    let inputArray;
    let outputArray;
    if (i === 0) {
        inputArray = [i / FPS, (i + 1) / FPS];
        outputArray = [1,1,1, 0,0,0];
    } else if (i === houseNodes.length - 1) {
        inputArray = [(i - 1) / FPS, i / FPS];
        outputArray = [0,0,0, 1,1,1];
    } else {
        inputArray = [(i - 1) / FPS, i / FPS, (i + 1) / FPS];
        outputArray = [0,0,0, 1,1,1, 0,0,0];
    }

    // Construct glTF animation.
    const input = doc.createAccessor()
        .setArray(new Float32Array(inputArray))
        .setBuffer(animBuffer);
    const output = doc.createAccessor()
        .setArray(new Float32Array(outputArray))
        .setBuffer(animBuffer)
        .setType('VEC3');
    const sampler = doc.createAnimationSampler(node.getName())
        .setInterpolation('STEP')
        .setInput(input)
        .setOutput(output);
    const channel = doc.createAnimationChannel(node.getName())
        .setTargetNode(node)
        .setTargetPath('scale')
        .setSampler(sampler);
    anim.addSampler(sampler).addChannel(channel);
});

io.write(OUTPUT_PATH, doc);

The result works correctly, using your original .gltf file as input:

scene_step.glb.zip (3.3 MB)