Low resolution reflections in FTEQW

[toneddu2000]

[mh]

This demonstrates exactly why you should measure milliseconds per frame rather than frames per second. It actually isn't a catastrophic framerate drop, it's perfectly normal.

At 500 fps a frame takes 2 milliseconds to draw.
At 250 fps a frame takes 4 milliseconds to draw.

The cost of drawing your reflections is therefore (4 - 2) an additional 2 milliseconds, which is also equal to the cost of drawing a normal frame. That's expected behaviour and it just means that the cost of scene traversal, state changes and issuing draw calls is the same in both cases. There would be something wrong if it wasn't.

Getting no performance increase from switching to lower-resolution cubemaps just means that you're not bottlenecked by fillrate.

[toneddu2000]

thanks mh for the explanation, I didn't know that kind of measurement. I learned something new about draw calls!
And what about my second question: could it be possible to show reflections on non planar surfaces?
Thanks again

[Spike]

'map $reflection' isn't intended for multiple surfaces (really just water and maybe the occasional imperfect mirror/glass pane). the problem being that reflections that can see reflections can see the original reflection and it all gets a bit recursive.
I'm not entirely sure if fte's batching is even aware of it...

as mh says, frametimes beat framerates because they are linear. in other words, division sucks. this is also true with your OPACITY thing - you should really have used a 0-1 scaler instead of a division-by-zero/really-tiny-but-still-not-0-scaler. it makes interpolation much easier that way.

reflections on curved surfaces are pretty much a nightmare. you can get away with ripples or other distortions if you're okay with the reflection potentially sampling things that are behind of offscreen (really off-fbo), but this should only really happen at the edges. actual curves however are too unreliable really.

precomputed cubemaps can of course reflect in any direction they fancy (including curves). and because the mapper specifies where the central point of the reflection cube is, they can avoid it being stupid like inside a wall or whatever. however, you lose paralax. when each point is assumed to reflect from the same point you do at least avoid the worst of the distortion.

[toneddu2000]