Everything is twitching in a weird way when i move around my scene, in the image attached is just a simple grid (no deformation applied) points are of place also twitching when i dolly,pivot etc. i had a pretty big scene open, in the scale of a city and often i had to zoom in a lot, even if i do spacebar h to recenter nothing changes. All this i think started when i zoomed in using shift right click to avoid clipping instead of just the middle scroll. Usually in other programs there is a setting for the scene scale that fixes these kind of problems.

This is a FP32 precision issue, which is pretty much resolved in H18 but unfortunately can't be backported.

twod
This is a FP32 precision issue, which is pretty much resolved in H18 but unfortunately can't be backported.

so why is this not happening in any of my other files? is it scale/zoom related?

Pretty much, if you take a relatively small object (say 1-10 units) and transform it very far away from the world origin (say 1M units), the fp32 points and transform lose some of the lower bits of precision. (Fp32 has 6-7 digits). That's why you end up with a bit of jitter on the points themselves.
H18 fixes this with a major rejigging of the glsl vertex shaders.

twod
Pretty much, if you take a relatively small object (say 1-10 units) and transform it very far away from the world origin (say 1M units), the fp32 points and transform lose some of the lower bits of precision. (Fp32 has 6-7 digits). That's why you end up with a bit of jitter on the points themselves.
H18 fixes this with a major rejigging of the glsl vertex shaders.

ok thats good but how did you get around this problem until h18? handling a really large scene like a city for example? i'm trying to understand if there is a better workflow for me right now. i suppose i could transfer my scene altogether to the origin and scale it down although that would affect many calculations.

You can use the “Hide other Objects” option and dive inside the object, and the object transform will be ignored. So if that was causing the large positions, you can at least workaround the precision loss while you're in that object. It's the icon menu between the shading mode and the viewport layout icons beside the path gadget at the top of the viewer.

twod
You can use the “Hide other Objects” option and dive inside the object, and the object transform will be ignored. So if that was causing the large positions, you can at least workaround the precision loss while you're in that object. It's the icon menu between the shading mode and the viewport layout icons beside the path gadget at the top of the viewer.

yes, that was the problem i was using “ghost other objects” and that messed everything up, as soon as i turned over to “hide other objects” everything shows up fine again, no twitching. thanks!!