Note that the WebGL build uses filameshio, but Android does not. Our
Android samples therefore do not yet understand the compressed format.
For web, I measured the before / after:
```
BEFORE: filament.wasm = 505796, suzanne.filamesh = 521476
AFTER: filament.wasm = 510915, suzanne.filamesh = 333489
```
Issue #558
When cmgen creates ktx files, it creates a pair: one with an _ibl suffix
and one with _skybox. This convention is now honored by FilamentApp.
Note that we already have several KTX environments in the repo, so you
can clone a fresh repo and do:
gltf_viewer --ibl={FILAMENT}/docs/webgl/pillars_2k DamagedHelmet.gltf
Note that we have several hundred files in samples/envs, we should
consider replacing those or copying the environments in docs/webgl
(which git would internally de-dup, due to content hashing).
(1)
Generating the C file (only used for WebAssembly) causes slowness in the
build so this makes it into an option. Also, we were flushing too often,
which made it even slower.
(2)
Using "static" in a header was causing symbol duplication.
This shows how resgen can be used for mesh data. It also removes the
MeshAssimp dependency from samples that were meant to be small and
self-contained.
We started to write our own implementation of mikktspace, but it
required an unindexed mesh for input. This was awkward because assimp is
already applying a pipeline of operations that includes tangent
generation and indexing. It felt reduandant to add our own pipeline on
top of that (unindexing => tangentgen => reindexing).
Since assimp's CalcTangentsProcess method is already producing
tangents that follow the orientation implied by texture coordinates,
this simply needs to be tweaked to match glTF. (flip the bitangent)
Also fixed a bug for the case where models have neither UV's nor
tangents, where we were calling norm instead of normalize. :)
* Revert "Rollback MeshAssimp enhancements."
This reverts commit b3dce967eb.
* Re-enable glTF support
* Start looking for texture ids at 1, not 0
* Detect if the importer is glTF
* glTF and regular materials both work
This caused regressions with some of our samples like vk_hellopbr:
- For the new 1x1 textures, RGB isn't accepted by Vulkan and Metal.
Currently these platforms require RGBA, although we plan on adding
reshaping functionality for the future.
- Too many texture samplers in a single shader, this causes a run time
error. This could be alleviated by creating an atlas.
- vk_hellopbr assumes that all materials have a "metallic" param.
Going forward, we plan on creating a new library that avoids MeshAssimp,
so for now let's just disable gltf_viewer.
For test coverage, ensure that one of our C++ based web samples
uses a filamat file instead of inc, because this is how the JS based
web samples will work.
This makes pre-zipped triangle wasm go from 747 KB to 741 KB.
The web build now invokes cmgen three times for each IBL: uncompressed,
S3TC (desktop), and ETC (mobile). Alternatively, we could enhance cmgen
to accept multiple compression strings, but per discussion with Mathias
we decided to keep it simple.
I decided not to use compression for the skybox in our web demos because
the quality is too poor (see PR image). I did not try playing with
compression settings, might be worth revisiting in the future.
This change will allow the skybox use a compressed texture format.
For now, the old internal format "RGBM" is still honored, but in a
forthcoming change we will replace the enum with UNUSED.
Due to an assertion in etc2comp, this unfortunately uses RGB8 instead of
RG11 but it still helps quite a bit (3.3 MB savings in the unzipped KTX
size).
This shrinks file size as follows, although it seems to darken the
rendered result.
```
1398209 Oct 2 16:22 ao.ktx
699172 Oct 2 16:20 ao_etc.ktx
1398209 Oct 2 16:22 metallic.ktx
699172 Oct 2 16:19 metallic_etc.ktx
1398209 Oct 2 16:22 roughness.ktx
699172 Oct 2 16:20 roughness_etc.ktx
```
At build time, mipgen now creates several compressed and non-compressed
variants for albedo.
For ASTC we use the ARM encoder, for S3TC we use the STB encoder. The
latter is somewhat limited so we may wish to investigate other libraries
in the future (e.g., AMD Compressenator).
At run time, we detect which of these variants to download, based on
available WebGL extensions. In practice, this means that desktop
browsers will use the S3TC variant and mobile browsers will use the ASTC
variant.
The makes unzipped albedo go from ~4 MB to 682 KB using S3TC.
Mobile support (ASTC and ETC2) is coming in a future PR, stay tuned.
Sometimes you want your KTX file to end in an extension other than
".ktx". For example, GitHub Pages applies gzip encoding to bmp files
but not to ktx files (which I think is consistent with nginx defaults).
This change makes it so that a deploy script can rename the files and
apply a simple string transformation to the HTML.
(1) Suzanne's normal map is actually linear but we were telling GL that
it is SRGB, so the shader was not reading (0.5,0.5,1.0) from a perfectly
flat normal map.
(2) --linear in mipgen was not honored when consuming PNG files.
(3) The build was not passing --linear to mipgen for the normal map.
To determine PNG vs KTX, we were looking at the file extension of the
asset name rather than the actual file path (which is a URL).
Also, le singe était trop sombre, so I added a call to setIntensity.
In Chrome, this reduces texture load time from 620 ms to 150 ms because
it removes the PNG decoding work for the surface textures. We are still
using PNG for the envmap, I'll fix that soon.
Many web servers, including GitHub Pages, automatically use gzip
encoding for these files. Over the wire these files actually are not
much bigger than the PNG, even though they contain miplevels.
Stay tuned for compressed textures, which should make this better.
