I think it is likely to do with the history of how and why the modes have been developed.
Others can explain better but the viewport mode that is called ‘rendered’ is rendered a bit like a computer game, ie the lighting is an unrealistic fudge and, I imagine, rendered by the GPU.
Using the render tool has traditionally used the rhino render engine which uses the CPU to calculate a higher quality image based more accurately on the lighting within the scene. I’m not sure what rendering technique has been used historically here but I don’t think it is raytraced. It appears to similar in some ways to the scanline renderer I used to use in another app years ago. This has always been far too slow to have as a live viewport display mode. It is also not as good as raytracing.
It is only fairly recently that raytracing could conceivably be performed in real time or near real-time. This, in theory should hopefully allow the two other tools / modes to be mothballed in due course which would remove the undeniable confusion that comes from there being two different images styles produced using tools called ‘render’ and a third by a tool called ‘raytrace’.
Now for hoping that raytrace mode and rendering speeds up a bit because the performance on my pretty new Mac is still really bad! I have to remember (this is vitally important) to not save and close a file with raytrace display mode activated. If I forget, the file takes FOREVER to load as Rhino prepares and starts rendering the raytraced view. So so painful.
In the latest RhinoBETA, you can use TestToggleTechDisplayMode to turn on some recent optimizations that may - depending on your feedback - make their way into a subsequent service release. You can run the command again to turn it off. As always, please report any bugs you see.
On my machine (mid-2018 15" Pro with 560X) I notice improvements in performance and no change in visual quality in all three modes, particularly pen mode. It’s not the best, but it is much better. Thank you!
I don’t use any of these except Blueprint which I believe is based off one of them (?)…
but yeah, the test command does improve this mode… without the TechMode test, there’s a slight delay prior to accelerating the navigation (using a trackpad which has a sort of acceleration/deceleration thing)
after running the test command, this little lag goes away…
also, if I TestMaxSpeed, I get nearly double the frame rate with TestTechDisplayMode toggled on…
Don’t be sorry, that is great. Also, yes blueprint would be affected by this change. I’m hoping to get this feature turned on by default in the initial service release, but there is a bug with blocks I need to fix first as well as another optimization that will speed up the drawing of the intersection curves.
not as spectacular as Jeff, but better: old vs new:
technical, pen, pen outline with the file posted earlier. Still in these modes this feels very laggy.
Also when rotating the viewport with the trackpad, when I give it a swing, there is a hickup after I release the trackpad. While swiping it kind of ok and after release also, but in between it stalls for a short moment.
Command: testmaxspeed
Time to regen viewport 100 times = 10.20 seconds. (9.81 FPS)
Time to regen viewport 100 times = 6.24 seconds. (16.02 FPS)
Time to regen viewport 100 times = 6.66 seconds. (15.03 FPS)
Time to regen viewport 100 times = 7.87 seconds. (12.71 FPS)
Time to regen viewport 100 times = 4.46 seconds. (22.42 FPS)
Time to regen viewport 100 times = 5.51 seconds. (18.16 FPS)
Those are still heading in the right direction. Results are going be very different from model to model right now as I still need to implement intersection wire drawing a different way. If the model has a significant number of intersections to draw, you won’t notice a big difference in performance.
I’ve updated to the latest beta (Version 6 WIP (6.16.19197.13284, 2019-07-16)), Rhino became unusable. Existing or new model, doesn’t matter, even if I create a simple box, beach balling between the clicks all the time.
Navigating also, I haven’t had issues before with shaded/wireframe, now it’s a disaster also, panning and rotating/zooming is useless - lagging and beachballing with each move.
Can you please provide steps for reproducing this behavior? 6.16.19197.13284 is behaving just fine here. I suspect your preferences have somehow gotten broken. You might try resetting them to see if that changes things. Make sure to save a backup copy in case it doesn’t change things.