Hi Mike, are those objects all stacked up exactly on top of one another?

If so then that's actually an expected consequence of the new multi-threaded display - it's just fundamental to how it works that there will not be the same ordering of processing as there was with a single thread doing the processing.

Things that are exactly tied for their z depth will end up being dependent on the order that they are drawn as far as which one "wins". That's not really a bug, it's just how the display mechanism works.

If you want to avoid that, the main way to do it would be to move the curves you want to have on top to be at a higher z level than the others - even if it's only by a slight amount that will avoid the "tied result in the depth buffer" type of problem that you are showing here.

Either that or if you want to have exactly-depth-tied things drawn in a specific order setting the DisplayThreadLimit=1 to turn off multi core processing would also do it.

But it's generally to be expected that you will see various kinds of "z fighting" flickering when entities are exactly stacked on top of one another, particularly with surfaces.

It's just a common thing that happens with video card displays in general, see here for more information:
http://en.wikipedia.org/wiki/Z-fighting


> Didn't one guy complain of "shimmering" triangles?

Yeah but I've been discussing that over private messages, and it turns out that it's also happening with v2 so it looks like some kind of video card specific issue, not anything related to the new multi-core processing.

- Michael

Okay, thanks...

...oh yeah, same deal on the home PC.
So we now know that the apparent "z-fighting" artifacts are a welcome byproduct of MoI's new multi-threading.

Like the old Alkaseltzer adds: "...if you see the fizzing, you know it's working!"

Hi Mike, you can also easily get z-fighting artifacts without multi-threading as well, it would just previously happen on overlapping surfaces before and not so much on curves.

In prior versions before multi-threading I'm sure you've probably seen this kind of thing with 2 objects overlapping each other and one of them selected or colored differently than the other:



That's z-fighting right there, without any multithreading needed. Multithreading just throws some extra spice into the mixture, particularly with curves.

Basically z-fighting is a display artifact but one that's a normal part of video card display technology. It is possible to do some things to control it, mostly by having the software automatically pull things forward by a little bit in z to influence the result. But it's a somewhat touchy thing because if you pull forward by too much it then can make things show that you really wanted to have hidden.

- Michael

Thanks Michael,

It's a great visual indicator of co-planar surfaces.

Now it's an added bonus for indicating coincident curves as well! :)

- Michael

;-) Aha!

Hello,

Very nice speed upgrade. I really don't get too wrapped up in numbers, my metric for stuff like this usually is being able to perceive a performance increase without a stopwatch. Great job, thanks.