White dots again..

[schnukas]

Hey there! i am relatively new in using my standalone maxwell studio 2.51 x64 software on a windows machine. i am too lazy to watch the 10 gb maxwell tutorial, but i learned how to set up lights and cameras and how to give the right scale to a material by myself. now if i set up a scene, the higher sampling level i take and the more time the render is running, the more of those white dots occur. cause of the fact that i dont know anything about material layers and reflectance, i presume my problem has to do with one of these things.

i hope somebody in here can explain the problem for some rendernoob like me

thanks in advance

schnu

[ATTACH=CONFIG]44560[/ATTACH]

[xEndlessxUrbiax]

Maxwell renders using the unbiased method. Are you sure those white dots don't go away if you let it render longer?

[schnukas]

yeah, could be. cant try it because my machine still randomly reboots, although i changed rams, graphics card and bought a bigger (600W) power supply. cpu temp is at 42°C after hours of rendering... got an amd 1055t 6core on a asus m4a785-td v evo. after one year of trying around it still f***s around... i wanted to buy one of the new macbook pros with 4cores, but now i ve seen about 1000 entries with freezing problems when maxing out the (osx!!) system...

I just wanna render when and how long i want!!!

sorry

[Brodie Geers]

It could very well be a material issue but it's hard to say without seeing the file. The first thing I'd look at is the glass material. Is it made with real glass or with AGS glass? Also, what is your environment HDRI or Physical sky?

 

There's a current issue with 2.5 where caustics aren't generated well with HDRI environment. It creates these sorts of white dots that very slowly converge but only after an unreasonable amount of time (only around SL25 they become recognizable as caustic patterns). To find out if this is your issue switch to Physical sky or go into Render Options -> Illumination & Caustics and disable Refl. Caustics and Refr. Caustics.

 

-Brodie

[schnukas]

hey thanks brodie!

I rendered it with physical sky, but now i'll try it with the Refl. Caustics and Refr. Caustics thing.

i found out that the preview shows that more of the white dots will appear, but they are getting less to the end of the render. there are so few white dots, that i can easily remove them in photoshop.

the havier problem now is that my machine isn't working correctly.

is there a newer version out than 2.5?

[Brodie Geers]

The current version is 2.5.1 but there has been word out for awhile about 2.6. Supposedly it was to come out around July.

[Guest 2PMVisuals]

Hey,

 

I'm not sure if you have this sorted now, but I have run in to similar things with Maxwell in the past so I can try to help.

 

In my experience these white spots tend to appear when some light in the scene (environment, hdri, emitter) has been set to an unrealistically high setting. Unlike the normal 'noise' grain that clears as the render goes on for longer, these white dots tend to appear and get worse the longer the render goes on. They seem to be an artifact created from the lighting value being set too high.

 

I notice from your screenshot that your Maxwell camera is set with an ISO of 100 and a shutter speed of 1/500. This is very high for an internal scene (even though you are looking towards the outside). In the real world a photographer would probably be looking at a setting of 100 or 200 for the ISO and 1/60 or 1/125 max for the shutter speed. Try adjusting your Maxwell camera settings to these real world values and you will probably see that your render gets way too bright. If so that is because your lighting values are set too high, causing the white dots. Try turning the lighting settings down to real-world values to create a realistic setting with the image and render again and you should find that the majority of the white spots will disappear. I've also found that images will render slightly (but only v slightly) quicker when the lights are set at realistic values.

 

MB