Feature/hatching

[ijlal99]

• Users can now instantiate SectionCapsPlugin along with their section planes to enable hatching on the scene
• This plugin supports multiple section planes and models on the scene

[xeolabs]

Thanks Muhammad! Only changes I'd like to make is to make all methods and variables that are used internally by the plugin private, and remove them from the TS definitions. Then it would seem to have a nice simple API, as an automatic background helper. Also, please add a method, like setEnabled(), so the user can disable/enable the plugin dynamically.

[xeolabs]

Got a strange little artifact when testing examples/slicing/SectionPlanesPlugin_Duplex_SectionCaps.html

[ijlal99]

@xeolabs this is something that is caused by objects that are not solids but classified as solids (I believe).

[xeolabs]

@xeolabs this is something that is caused by objects that are not solids but classified as solids (I believe).

Gotcha - can you make it not make solid caps for non-solid objects?

[ijlal99]

@xeolabs that's how I am currently doing it. I am only generating caps for objects that are classified as solids.

const isSolid = sceneModel.objects[key].meshes[0].layer.solid ?? false;

[xeolabs]

@xeolabs that's how I am currently doing it. I am only generating caps for objects that are classified as solids.

const isSolid = sceneModel.objects[key].meshes[0].layer.solid ?? false;

Aha I see. These objects are wrongly classified.

[ijlal99]

I am not sure if I can do much about it but would love to hear your ideas.

[xeolabs]

Here's an XKT with properly classified solids:

model.zip

However, it would also be good to have an example that demonstrated solid caps with a programmatically-created SceneModel, like this example: https://xeokit.github.io/xeokit-sdk/examples/scenemodel/#vbo_instancing_autocompressed_triangles

The idea is that we always have a minimal example that's easier to debug (way easier than with an IFC model).

Note that you'd need to change the primitive types on the SceneModel meshes in that example to indicate that they are solids.

[ijlal99]

1. I fixed the issue with hatching that was causing some random artifacts to show alongside the hatched model.
2. I have added another parameter with 'opacityThreshold' for user to control hatching the objects that have opacity above this threshold.
3. There was a bug in the implementation of getEachVertex that was not correctly transforming the vertices.
4. I have added a simple example as suggest by @xeolabs but the example with skt model is also there. If you guys want, I can delete it.

Attached is the result of how hatching looks on previous xkt model, the model provided by @xeolabs and a more simpler model.

[MichalDybizbanskiCreoox]

I'd suggest reorganizing commits a bit, to avoid introducing unstable state of the repository.
An example would be
8acb036#diff-3986a1ed352df2aeac30a1e1db927c1a2285e4ce219ec61dfa57406f01ef4983
which introduces a import html2canvas from '../../node_modules/html2canvas/dist/html2canvas.esm.js'; regression, that is rectified by
e143581
The latter could be merged with the former to prevent introducing a temporary regression to the master branch.

[Amoki]

Could it be possible to color or texturize the hatch depending on the IfcType of the object?