Light leaks on intersecting edges

[Jpjapers]

There was a thread about this a few weeks back but i cant find it anywhere.
Im getting light leaks on intersecting edges when rendering.
Its definitely a corona problem because it doesnt happen with ART.
I know you guys were looking at it but couldnt replicate. I can upload the scene if necessary.

Thanks
Jack

[Ondra]

yes, scene, please!

[maru]

Is the scene far away from scene origin? (e.g. 500km from point 0,0,0)
What are your scene units and system units?

[Jpjapers]

Is the scene far away from scene origin? (e.g. 500km from point 0,0,0)
What are your scene units and system units?

Scene and system units are set to mm which has caused issues before. It was pretty far from the scene origin yes. Ill move it and re render and let you know whats going on and ill upload the scene once its rendered so you can have a poke around anyway

[Jpjapers]

Moved close to scene origin and no light leaks. I assume its something to do with accuracy at large distances from the origin. Do you still want the file?
Thanks :)

[maru]

No need for the file if the issue is solved. Unless Ondra wants it.

So I would suggest always building the scene around scene origin, and also using proper scene and system units. If it's something large, then meters or centimeters should work fine, but probably not millimeters.

[Jpjapers]

Yeah ive spoken to autodesk this week about the units stuff and we are going to change to cm as a team because when youre dealing with 50,000 square foot spaces and using mm it creates some weiiiiiiiiiird problems! Thanks for the help!

[burnin]

Note:
(you can skip intro;)
Precision problems (errors) are more common than majority knows or even thinks about. In our line of work those are architects & archviz artists. Many practicing some crazy-mixed scaling, XS or XL units and coordinating projects all over but around center. Then when they are told about usual answer follows: "Everyone is working like this. We haven't had any problems." Yes, for making few images, printing paper plans & few posters this is more than OK. Now do the earthquake, fire, lighting, emission simulations...
In short why there's a professional need for double precision, ECC memory... especially for financial & science computing (simulations of reality), where such mistakes can't be tolerated.

What some of us do, is simulating light to arouse emotions with the artistic style in mind. We're caught somewhere in between design, film, games, engineering, science, medicine, magic, cooking, hunting, gathering, philosophy and art.
No joke :D

So bare in mind as one of the basic principal in rendering/CGI - Optimum:

Coordinate the scene in minimal space possible with center of gravity in, or close to origin (0,0,0).

+ Makes the scene render faster, orient easier, coordinate better, prevents bugs (precision errors)... ;)
 

[Jpjapers]

Note:
(you can skip intro;)
Precision problems (errors) are more common than majority knows or even thinks about. In our line of work those are architects & archviz artists. Many practicing some crazy-mixed scaling, XS or XL units and coordinating projects all over but around center. Then when they are told about usual answer follows: "Everyone is working like this. We haven't had any problems." Yes, for making few images, printing paper plans & few posters this is more than OK. Now do the earthquake, fire, lighting, emission simulations...
In short why there's a professional need for double precision, ECC memory... especially for financial & science computing (simulations of reality), where such mistakes can't be tolerated.

What some of us do, is simulating light to arouse emotions with the artistic style in mind. We're caught somewhere in between design, film, games, engineering, science, medicine, magic, cooking, hunting, gathering, philosophy and art.
No joke :D

So bare in mind as one of the basic principal in rendering/CGI - Optimum:

Coordinate the scene in minimal space possible with center of gravity in, or close to origin (0,0,0).

+ Makes the scene render faster, orient easier, coordinate better, prevents bugs (precision errors)... ;)

Ive been saying exactly this for about 2 years in my current job but because theres never been problems before they were reluctant to change. when i pointed out that by working in mm and using the default accuracy you are asking max to calculate to about 10 billionths of a mm depending on scene scale and to put that into perspective an atom is alot bigger than that, they started to come round to my way of thinking.
We have ECC memory in all of our workstations but the problem is most of the time the CAD planners will move their design around in cad space and then when it comes into Max its nowhere near the old design in Max space so it becomes a constant struggle to realign stuff. Such a pain in the ass!

Thankfully ive managed to get the team to come round to my way of thinking and finally switch to more useable units.

[ktulu]

... but the problem is most of the time the CAD planners will move their design around in cad space and then when it comes into Max its nowhere near the old design in Max space so it becomes a constant struggle to realign stuff. Such a pain in the ass!
...

Have you tried exporting from CAD with a user coordinate system defined somewhere close to the actual design? We do it all the time in our office (civil engineering & landscape architecture). Our CAD files are georeffed, thus typically have huge coordinates which max can't handle well so we define a UCS and export to max using this one.
Everything works like a charm and aligns perfectly between the two environments.

[Ondra]

resolved - it is always possible to break a scene by moving it further from origin