Why 3dsMax 2017 mray Rendering stops [hanging] at 98.1% Photon Emission ?

minus0

It is a simple scene:

a) A wall

b) One Lens(refracting)

c) One light(photometric light)

The light is oriented at the wall, and between the wall and the light, is the Lens(glass object)

Why mrRendering stops[stalling,hanging] at 98.1% Photon Emission when I am setting IOR =2.0 ?? [Lens_01 IOR=2.0]

If I set the Lens_01 IOR= 1.5, everything renders fine.

I have attached the scene. I use mental ray materials, mr photometric lights, FG+GI+Caustics.

I get multiple errors saying the same thing:

"RCGI 0.7 40 MB error 361053: no photons stored after emitting 1000000 photons from light "PhotometricLight001|Light" (tag 1143): canceling emission job"

But the rendering is fine, with the IOR settled at 1.5 , no matter the errors. i have tried the same scene on other systems with different version of max like 3dsMax v2013,v2016,v2017. [Does anyone use 3dsMax 2017? i have tested it. Is v2017 suppose to be a joke? seriously..]

i still get the freezing problem when Photon Emission is calculated, sometimes it stops at 81.4%, sometimes at 97.1%

Normally the frame renders very fast 20seconds, i understand that it is something wrong with the photon emission? and with the refracting glass, but i cant figure it out what it is. the Normals seems to be..normal. the light is compatible with mental ray engine, the material of the wall is fine. i have tried with default low settings and with custom settings regarding FG+GI+caustics.

minus0

i am not sure if this could be useful for anyone, but i Found the answer, at least i think i did.
After several days of testing different scenes(and same scenes on different max versions) on several workstations(with different OS's), i found out that the problem is 3ds Max 2017, to be more specific, the mental ray engine inside max2017. Somehow Max is freezing-pending-hanging while rendering simple mental ray scene, resulting in displaying an error message that says: mental ray engine has become unstable, it is recommended to restart max.
this happened with the latest service pack installed, SP2.
So the solution was(is) to stay away from 3dsMax2017. I loved the way they changed the UI, the viewport performance seems to be a lot better, but is something wrong with the mental ray engine as i encountered the above described problems, on Win7 and Win10. I have noticed that some people didnt have any problems using v2017 on Win10. Lucky them. From my experience i can only say, with disappointment, that the team who worked & released 3ds Max 2017, didnt finish it. Releasing a product(green light for the market) means it is ready, it is finished.
When you need service packs to patch the final product already released, it means you didnt make a good job, it means "you" didnt finish it, it means you failed to accomplish the main objective.
i am aware that making(improving) a complex software involves hundreds of people and many months of hard work, but the principle is simple: dont release an unfinished product. it seems that Autodesk doesn't care about this, they want money in the bank, every 6 month, for unstable unfinished products. It's like selling cars with major engine&steering  critical problems and let the owner find out while he is driving it, after he already bought it of course.

spacefrog

So you have a perfect repro scenario here and even invested your time and energy to test various options. The only one info that is missing here is:  Did you report the bug to Autodesk ?
http://download.autodesk.com/us/support/report_a_bug.html?SelProduct=3dsMax
It's of no use to post such extensive analysis on a user to user forum only. You should report it too

minus0

@spacefrog , When Autodesk will pay me good money, i will report to them the errors/bugs that i found. You are right, i invested time and energy in testing and finding the problem(in order to search for a solution), and somehow i regret it, but i had to do it, i needed to know(to test it, to see it), initially i thought that the problem is caused by the OS or the drivers. Well, i was wrong, it seems that it is the 3dsmax2017.
Like i said, why shall i bother and "work for autodesk", for free?
One of your answer could be: "reporting the bugs to autodesk, helps them fix the product i use, therefore it's beneficial for me in the end"
I am sorry man but i don't think it is fair, if you think that "i" should do their job, and not get paid.
Autodesk is a huge beast as you said, i agree. That's why i think they don't care so much about making a complete-working-stable product, because they release a final product with major/multiple problems. The existing of Service Pack 1 & 2 proves my above affirmation. They are not a small company trying to create something very complex, even so, the basic rule is, if a product is not working properly, you shouldn't sell it. It's not like ten poor guys are trying to make a complex product inside a small garage and in the end the product has errors/bugs. And people say, "its fine, lets help these guys".
Autodesk has a lot of money(i don't envy them), you don't have to be one of their account manager to see that. They can afford to invest time&money in making a good final product, but they don't want to.
@spacefrog, Would you buy a new car with an engine that very often suddenly stops while you are in traffic? And would you call it a fine piece of car? a great release?