Technology Preview 2 :
- Finalize Preetham's model usage
   => Update all fields when "auto from daytime" is selected
   => Apply model to atmosphere (aerial perspective)
   => Find a proper model for night sky (maybe Shirley)
- InputInt doesn't honor small_step.
- Keep skydome lights in cache for a render.
- Disable form fields when no layer is selected.
- Add buttons to restore "auto" default values in tabs and dialogs.
- Replace zone ranges with curves (with curve input and curve dialog).
- Interface for textures thickness, slope_range and thickness_transparency (and correct slider ranges).
- Add "hardness to light" and shadow control ("minimum lighting") to material.
- Render tab previews should not rerender when changing render options.
- Add layer sorting/naming.
- Add logarithmic sliders for some float values.
- Improve previews.
   => Add a right click menu for toggles and modes
   => Add user markers on OSD
- Add a zone editor dialog for localized textures.
- Add a terrain modifier dialog with zones.
- Use the curve editor in noise editor
- Add a noise filler (and maybe noise intervals ?).
- Fix the distorted sun appearance.
- Improve curve editor.
   => Add curve modes
   => Add logarithmic mode
   => Add zoom and scrolling
- Fix "RGB parameters out of range" (and segfault) on preview while moving render params fast in render tab.
   => May need to change the updateData system.
   => Previews need to be paused while updating data.
- When there are two previews in the same view, balance rendering between the two.
- Lock some previews together (eg: terrain height and colored preview).
- Find a new licence.

Technology Preview 3 :
- Restore render progress.
- Implement High Dynamic Range.
- Implement Sub Surface Scattering for water.
- Use bicubic interpolation for antialiasing.
- Allow for larger renders/antialias (will need several two-pass chunks).
- Add basic vegetation system ?
- Texture shadowing and self-shadowing ?
- Add a progress indicator on previews.
- Multi threaded first pass.
- Mark modified tabs and ask for losing modifications (idem for layers).
- Fix potential holes in land rendering.
- Progressive final render (increasing resolution, for second pass only).
- Propose several backgrounds for water preview (grid, sinus...).
- Water and terrain LOD moves with the camera, fix it like in the wanderer.
- Improve 3d explorer
   => Restore LOD and intelligent poly count (and raise max tessellation)
   => Interrupt chunk rendering when quitting dialog
   => Don't display the water if it's below all ground
   => Try to overcome the near frustum cutting
   => Disable specular lighting (dependant on camera location)
   => Add toggles (for water...)
   => Max texture size should depend on GPU memory available
- Interrupt preview chunk renderings that will be discarded at commit, or that are no more visible.

Release Candidate :
- Polish all features and UI.
- More translations.