Very slow render

[art-MIXER]

Hello everyone.
Please help me with my problem very slow rendering. Very slowly out noise, so that he would have gone completely, you need 400-500 passes, but the time he calculates for this task more than 16 hours. For me, it's just an incredibly long time. Maybe I'm doing something wrong in the structure of the scene. Although the models themselves, in principle, simple, in a scene about 12 million polygons for the entire two-storey house. made of insulating glass window with two panes have a thickness (a thin and tried with a polygon, but the difference was minimal) as in windows are portals on the room side, immediately after the glass. Materials virtually all simple CoronaMtl, blend try not to use it. What is remarkable, with portals estimated time shows a little more than without them. In the light used sky and the sun, the sky defaul, soft sun with intensity 0.2. Just in the interior are simple CoronaLight plane next to each lamp, their 25-30 around the house. Background image behind the windows, a simple self-luminous material, which does not participate in the global lighting. Almost all of the materials from the albedo of 0.8.
The processor on which I calculate the i7-2600k with 32GB of memory.
I would be very grateful to any advice that will help me reduce the rendering time.

Best regards, Alexander.


Crop 1:1 - 143 passes - time 6:30 - UHD + PT16 + LSM2


Another view

[Juraj]

Nothing unusual for me, 2mil ray/s is quite what I average on single i7 (although twice faster from yours). In interior with lot of specular surfaces, things can get slow...

I do suspect the curtains. What happens if you remove them ? What does their material look like ? Did you also kept default MSI (20) ? Keep in mind Corona calculates MSI with the exposure you start your render with, so always start final render with correct exposure (Don't change it +3/-3 or whatever after start, only do that for test renders).

[art-MIXER]

I almost always use the default settings. Now I also have all of the default, but in the end I still LSM changed from 2 to 4, because the direct light was noisier than the global illumination.
I was literally exposure +1/-1, but thanks for the advice, I did not think that estimation occurs prior to rendering.
I've just fallen into despair with such slow miscalculation, do not have time at the stipulated time to count quality and without noise (





I honestly tried to hide the curtains and the speed difference calculation was also very small

Curtain material

[Ludvik Koutny]

I once disabled shadow casting for curtain objects and it created some super high albedo object that slowed down rendering extremely. Another problem could be misplaced portals, if you use any.

[art-MIXER]

Portals I deleted because they are contrary added render time. I will try to play with the values of the albedo, maybe it will help me.

[Stan_But]

Looks like Ondra needs to do code forced placing portals (; Especially in the such cases
Looking on the such noise some thoughts come that maybe this is the work of  lights with objects before them

[moadr]

I would definitely try to render the scene with the curtains hidden. That can slow down things there (once I had a not properly set up material for that and it made things really-really slow). If the render time gets better after that, than you can try out some other methods to set up your curtain materials to keep the normal render time.

[Ludvik Koutny]

Portals I deleted because they are contrary added render time. I will try to play with the values of the albedo, maybe it will help me.

You did not understand me. I was trying to say you should check if any of the objects in your scene don't have disabled shadow casting in object properties.

[art-MIXER]

No, I deliberately did not do it, but just in case I recheck again )

[maru]

Can you show:
-how the lights are made
-how the background material is made and to what object it is assigned


-are you using DoF in all your shots?

Also, there is some strange light visible "coming out" of the drawers. Looks like cache error? Maybe there is something wrong with the models?

[PROH]

+ can you show your window glass material. Is refraction 100%, or do you use Corona Ray Switcher for the glass?

Note: I know you now disabled the portals, but according to your description, there were placed "incorrect" (not following the guidelines). They should be placed on the outside of the windows.

[art-MIXER]

+ can you show your window glass material. Is refraction 100%, or do you use Corona Ray Switcher for the glass?

Note: I know you now disabled the portals, but according to your description, there were placed "incorrect" (not following the guidelines). They should be placed on the outside of the windows.

[art-MIXER]

Can you show:
-how the lights are made
-how the background material is made and to what object it is assigned


-are you using DoF in all your shots?

Also, there is some strange light visible "coming out" of the drawers. Looks like cache error? Maybe there is something wrong with the models?

- Light is made simple CoronaLight plane, above and below the flat lamp, surrounded by stands on Sun + Sky



- Background made outside the cylinder and it appointed self-luminous material



- Yes, in all its frames I used DoF (time difference with him and without him, too insignificant)

- No you are wrong, everything is wrong with the models and the light falls right there, he's not the boxes))) just now with a great noise so it seems. There at the bottom of the base made of stainless steel and it flare of light behind the camera, and the right on the front of multipath something out of the windows on the background

[romullus]

Plug BG material to CoronaRaySwitch material's reflection, refraction and direct slots, leave global illumination slot empty. Now assign that RaySwitch material to your BG plane. That should boost your render times quite a lot.

If you have unchecked some settings under Rendering Control in object properties of BG plane, set everything back to ON.

[ecximer]

Why do you set glass IOR as water IOR?