Discussions about Qt3D
I am interested by Qt3D in a case of a professional project. Qt3D seems to be able to help us to fix a lot of issues with our current 3D engine. As we are targeting all platforms we are concerned by performances and compatibility.
The FrameGraph can be pretty useful for us to change the rendering pipeline and adjusting it to our targets without increasing by much the maintenance cost.
My main interrogations are about the core part:
- Does Qt3D support Angle?
- Can we add our mesh and material loaders?
- Can we update geometry of meshes and use GL_DYNAMIC_DRAW equivalent?
- Are compressed textures supported (pvrtc, dxtc, etc)?
- Does shaders support float precision (highp,...) on mobiles?
- Do Qt3D use glsloptimizer?
- Am I right to suppose that models are sorted by materials, front to back,...?
- Are meshes combined into a single one when possible (sharing same material and render group,...) ?
- Are transparent meshes split when intersecting and sorted?
- Does the scene graph camera make culling with AABB of meshes or something else, to reduce the number of draw calls?
- Why documentations use near-realtime term instead of simply realtime? Are performances not enough good?
- Does it impact performances to create FrameGraphs in QML instead of c++?
- Can we do an off-line draw to save it to a file? We need to be able to make thumbnails of user draws.