Lighting doesn't reflect real-time

[Skippy-INC]

I've ran into an issue between the final render and the real-time image.  The final renders lighting is very harsh. but the real-time shows a smooth lighting against the wall. 
What do I need to change in order for the final render to be like the real-time?

[KeyShot]

If you use maximum samples as your final rendering method then the result should match the realtime output.

[Skippy-INC]

Ok so i tried your suggestion and it did work but took a long time, well over an hour.  How would I get the time down?  Im looking to keep my render time at or under 30 min.

[Esben Oxholm]

Your rendering time depends on a lot of factors:
1. The type of scene you're rendering. Interiors are heavier than product shots.
2. The type of materials in your scene. Transparent, semi-transparent and translucent materials are heavier than opaque materials.
3. The type if lighting you use. Physicals lights are heavier than using HDRI's.
4. Using DoF adds a lot of rendering time.
4. The resolution you output to. Remember that if you double the height and width of your output, you quadruple the amount of pixels and thus the rendering time.
5. The rendering mode you are using. Especially in the advanced setting, factors like anti-aliasing, global illumination and DoF can add a lot to the rendering time.
6. The CPU of your computer. The more (and faster) cores you have, the shorter rendering time.
7. Probably some other factors that I haven't covered above.

Any chance you can show your scene and rendering settings?
That will help us to give some more specific suggestions on how to improve the rendering time.

Cheers,

[Skippy-INC]

Heres the first image.  its very simple as interiors go.  Square box with 2 windows on the left and a light plane outside of that.  below that are the settings.  Im assuming that material samples might have an effect as well but those have not been changed from normal.  The last image is a general overhead of the scene.  I do the final renders with the roof on, it was removed to show all the parts in this scene.

[Will Gibbons]

A 3K image of an interior taking over an hour is not terribly surprising. What kind of machine are you using? You're expectations may be a bit optimistic depending on your hardware setup.

What is the processor in your computer?

[INNEO_MWo]

I guess it depends on the area light sources. These are the heaviest or slowest type of physical light. You'll see that in the heads up display, when you turn off the area light the FPS should be higher. I don't know which light preset do you use. Try the simplest one, activate global illumination and Ray bounces about 4 or 6. Activate interior mode and play with the HDRI editor using pins. Then let the live view port clear the scene and take a look to the sample rate. You can use the render region cropping the view port to a difficult area. That is faster then clearing the entire scene. Or you can use max time render option with let's say 5 hours in a smaller resolution and let it run in background mode (always faster then standard). If the render is clear enough, you'll notice the sample rate in the bottom right corner. This value can be used for the final render.

Hope that helps a bit

Cheers
Marco

[Skippy-INC]

A 3K image of an interior taking over an hour is not terribly surprising. What kind of machine are you using? You're expectations may be a bit optimistic depending on your hardware setup.

What is the processor in your computer?

Its a HP with windows 7, the processor is a Intel CORE i7-4790K CPU @4.00GHZ
The graphics card is a GeForce GTX 970

[Will Gibbons]

I think you've gotten some decent replies here that hopefully explain your results a bit. Your processor has 4 cores, 8 threads. This is on par with say, a macbook pro or similar laptop. The graphics card will not affect your render times since KeyShot only uses the CPU.

My previous desktop had 6 cores, 12 threads and decent interior renderings might take upwards of an hour, but I seldom render larger than 1920x1080. My new machine has 16 cores, 32 threads and it'll render the same image my old one did in one hour, in about 25 minutes.

If you're going to be doing lots of interior renderings and you want them to look realistic (meaning having nice shadows and global illumination), you may want to consider a hardware upgrade. KeyShot doesn't require powerful hardware, but some scenes simply take longer. Jewelry and interiors are near the top of the list of scenes that take longer to render.

Hope that helps shed some light on the subject.

[Skippy-INC]

Thank you all for the different replies, they have been very helpful.  After some experimenting and tweaking I was able to find a middle ground by adjusting the lighting samples and image size to give me a clear render in a decent timeframe of 30-min.  I am definitely considering upgrading the CPU for better performance- it struggles to run both 3D modeling (Solidworks) and Keyshot at the same time. 

Many thanks for the replies!   

[Will Gibbons]

it struggles to run both 3D modeling (Solidworks) and Keyshot at the same time. 

FYI, every machine will have this problem. By default when KeyShot is running, it's using 100% of your CPU. You need to manually change the CPU usage in KeyShot to leave some resources for other programs. (drop-down menu in Ribbon of KeyShot UI) If you have anything else running (your operating system, apple itunes updater, adobe CC updater, spotify, chrome, email, etc. - many of which run in the background) you won't have enough resources to run everything smoothly.

I strongly recommend pausing KeyShot every time you use any other application. I also recommend closing every other application that you can when working in KeyShot for best performance.