I still use Caligari trueSpace 6.6. My computer has an AMD FX 6100 six core CPU, 8 gigs DDR3 and a nVidia GTX 1050 GPU. Windows 10 Pro x64. trueSpace is 32 bit.

Recently I've noticed that rendering in trueSpace has become extremely slow, slower than it was with this and earlier versions of trueSpace on much slower computers. Solid view (showing the object colors and textures in realtime) in Direct3D mode is fine, no slowdown there.

The issue is when I click the buttons to render object or render scene it slowly goes down the screen from top to bottom with a sort of progressive 'window blind' effect, taking about 30 seconds. What's different from what it used to do is that multi-stripe effect, like it's processing chunks in parallel and doing a really bad job of optimization.

What it used to do (quite quickly) was just render the screen top to bottom, one line after another, no horizontal stripe effect.

There have been a couple of recent updates to the nVidia drivers. Could be they've managed to un-optimize or are deprecating support for older DirectX functions?