Draw models as lines instead of fill - wireframe like

[rrocav3]

Is there a way to show lines that conform the faces instead of the model faces?

SceneKit like:
node.geometry?.firstMaterial?.fillMode = .lines

OpenGl like:
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)

Expected result:

Thanks!

[ThomasGorisse]

Hi,

It sounds possible within Filament and Sceneform gives you access to the FilamentAsset directly.
Filament only provides a wireframe representation for the bounding box.

So this Filament PR: google/filament#942 by @prideout shouldshould not match your need.
You can then get the bounding box Wireframe Renderable from your gltf object.

The only thing missing is the java link to this cpp function inside FilamentAsset.java:

/**
 * Lazily creates a single LINES renderable that draws the transformed bounding-box hierarchy
 * for diagnostic purposes. The wireframe is owned by the asset so clients should not delete it.
*/
utils::Entity getWireframe() noexcept;

Could you make a little quick PR on the Filament repo and link it here?

[ThomasGorisse]

Sorry, I just saw the function doc and it seems to only get the Bounding box wireframe.

@prideout can you confirm that there is no actual way to get the object wireframe?

[prideout]

Right, that's just a bounding box. Filament's core API does not support glPolygonMode, that might be a feature request you could make over on the Filament github page. (This would be an actual core Filament feature, not a gltfio feature.)

[rrocav3]

Hello @prideout I currently open a thread in filament for asking this google/filament#4558
Romain said I have to handle it for myself by using a custom material and I try to follow a guide with no success. I think opengl can handle it for itself as long as I find other samples rendering wireframes like https://github.com/the3deers/android-3D-model-viewer

Thanks in advance!

[prideout]

Apologies, Romain is correct, Filament is mobile first and it must support OpenGL ES class devices. Therefore the wireframe needs to be rendered using a method other than glPolygonMode.

[rrocav3]

Sure, I see glPolygonMode is not in OpenGL ES but thought this can be done by filament using another method.