This feature adds one new method to `FilamentAsset` and uses it in our
Kotlin, JavaScript, and C++ helpers:
utils::Entity popRenderable() noexcept;
This pops a ready renderable off an internal queue, or returns 0 if no
renderables have become ready. It provides a simple way for clients to
gradually add renderables to the scene as they become ready. Previously
clients could only get the entire list of entities, regardless of
whether they had Renderable components or complete textures.
To facilitate this feature, this PR adds a new internal-only class to
gltfio called `DependencyGraph`, which is a temporary object used for
bookkeeping during the asynchronous load.
`DependencyGraph` discovers ready-to-render entities by tracking the
textures that each entity depends on. This is a graph because
renderables connect to a set of material instances, which in turn
connect to a set of parameter names, which in turn connect to a set of
texture objects. These relationships are not easily inspectable using
the Filament API or ECS.
We were already using jobs for decoding PNG and JPEG files, but we were
doing a join. This add three methods to ResourceLoader that allow
clients to amortize the decoding process across multiple frames, even on
single-threaded platforms like WebGL.
This PR adds async loading to the following demos:
- samples/gltf_viewer (now shows a progress bar in the UI)
- android/sample-gltf-viewer
- web/samples/helmet.html
Fixes#1876.
In my first attempt I kept the multiple project-level dependencies in
each sample's `build.gradle` but that resulted in a gradle error
concerning multiple copies of the same SO file. To work around this
we now append to "srcDirs" to bring in Java dependencies rather than
using project-level dependencies.
The new APK contents are now much more reasonably sized:
libfilament-jni.so 981 KB
libgltfio-jni.so 817 KB
libfilament-utils-jni.so 96 KB
Previously this was:
libfilament-utils-jni.so 1.8 MB
libgltfio-jni.so 1.8 MB (unused)
libfilament-jni.so 1 MB (unused)
Fixes#2070
This reduces the LOC of our gltf-viewer app from 260 to 146. This could
have been more, but I feel this provides good balance between
flexibility and convenience.
The raw gltfio API involves multiple objects (FilamentAsset,
AssetLoader, ResourceLoader) whereas the ModelViewer has a simple facade
consisting of two methods, one for GLB and one for GLTF. The underlying
gltfio objects are available via non-settable properties.
