[Interest] [QT3D] 3d Object and texture loads

[Sean Harmer]

On Tuesday 24 May 2016 10:36:30 Pierre Chicoine wrote:
> I believe I read somewhere in connection with Qt3D that there was a more
> organic object and texture type that loads faster into a mesh object that
> did not go through a heavy parsing stage. Is that accurate or should we
> continue to use obj or 3ds types for objects and jpg or png for textures?

For the Mesh element, Mauro is currently working on extending it to use a 
plugin system to support more than just OBJ. He is adding support for loading 
a named mesh from glTF initially but we may well add support for FBX too if we 
can find a nice way to handle the licensing around the fbx SDK. We may well 
also support a small binary format that is essentially a dump of the raw VBO + 
index data plus a small header describing it. This of course will require 
tooling to build such files at build time or as an offline step. We are looking 
at this for Qt 5.8.

For textures, if your hardware supports it, there are various compressed 
texture formats - I've had good results with BC6/7 formats. You may also wish 
to assemble multiple tetxure images into a single texture file (and resulting 
object) e.g. by creating texture arrays, cubemaps, cubemap arrays, plus 
mipmaps and storing these into a single DDS file.

We are also looking at adding cross platform tooling for creating such 
textures for 5.8. For now though, you'll need to use some other tools such as 
those provided by microsoft (see https://github.com/Microsoft/DirectXTex
).

When using a lot of textures, the cost of performing the PNG decoding really 
adds up, but worse is the resulting memory usage. Compressed textures help 
with both.

Cheers,

Sean

> 
> Pierre Chicoine

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