3DGS is really really behind all others in terms of terrain !
It's like prehistoric terrain making with 3DGDS when other 3D package have standard ones.
We have only a shader multitexturing that is really really basic.
Take BV engine it has complete terrain editing/painting tools
(done in some months or less after users requests

!
AND YOU CAN PAINT AS MANY LAYERS AS YOU WANT (that's to you to choose performance, number of layers ..)
Pfffff 3DGS as 3 that's good , but if it was user too choose the number
it would be lot more better.
Torque has that from years.
well , i hope 3DGS will have one decent real terrain editor some day.
even RPG games deliver terrain editors for moding (Titan Quest, Never Winter Nights 2 , Oblivion etc ...)
why 3DGS is soo sooooo behind for terrain ?
Like always my bad talking , it's just waht i feel when i use 3DGS and others
3D packages !
