render artifacts - large scene scale and distance from origin

[WAJORRO]

Hi.
Im working on large scale scene (about 50 km2) and im getting render artifacts on objects witch are far away from origin. Errors are most noticable on refractions. In system unit scale resulting accuracy is 0,002 m for objets that are 25000 far away from origin so it should be ok. I attached picture what happens if i move object on large distance.
It is normal behaviour? What caused it?

Im using 3dsmax 2020 and vray gpu next

Thanks for help.

[theedge]

Hi,
Have you tried setting your system units to meter ?

[WAJORRO]

Yes - artifacts still appear

[theedge]

Sorry, just to double check : I am talking about the dialog on the right on your screen grab, where you have set 1 unit = 10,0 centimeters. You tried setting system units to meters there ?

[WAJORRO]

Yes i tried almost every option cm, meters, km

[theedge]

How are you making your tests ?
You must set your system units on a new scene and then start creating or importing your geometry. Changing system units in an existing scene is not recommended.

[psanitra]

Are you sure you are changing the system units properly? Opening your existing file and changing the units from CM to meters is not the right way to do it. Safe/clean way to change to different units is this:
1)Start new max, change the system units to meters. no not save any file, just close max.
2)Start new max again, this time when it starts it will be in meters. Merge your existing file into this blank scene and save it under new name. Now you are properly set in meters.

[Morbid Angel]

There is no work around about value truncating in 3ds max since its single float precision. Changing ray bias value in vray to a value other then 0 may help, but the further away from origin you are the worse it becomes. The only solution is to move objects back to grid origin.

[WAJORRO]

ok, so I made everything from scratch - changing units setting, restarting max and creating new test scene. Results are the same. Please take look at attachment.

[WAJORRO]

There is no work around about value truncating in 3ds max since its single float precision. Changing ray bias value in vray to a value other then 0 may help, but the further away from origin you are the worse it becomes. The only solution is to move objects back to grid origin.

bad news ok, thanks for help!

[theedge]

bad news ok, thanks for help!

Indeed.
If it’s any consolation to you, porting 3ds max to double precision is flagged for future consideration on the 3ds max ideas board. But so are 500 other ideas... so... fingers crossed ?