Strange rendering times outcome

[zooropa]

I already opened a topic regarding issues of my scene. This time I thought was worth to open a new one since it is dealing with a different aspect of Keyshot.

Yesterday I left a scene rendering since afternoon till now...around 18 hs. The dimensions for the render 2560 x 1600

After 18 hs the outcome was the render window like this:



143 samples ...in 18 hs is not possible, not even with the slow performance I was experimenting in the progressive render (the actual KS viewport).

At the same time the file...looks way better than my 600 samples in KS viewport.

When I tried to finish the render asked me if I wanted to stop it...so for KS was not finished.

I am a little bit confused about what is happening. Is it a bug ? Did the render finished and KS was not understanding it was finish ? If the outcome is just 143 samples...hard to believe .
Yesteday I was dealing with the crazy graininess (in my other topic) at much much higher samples.

This (attachment) is the outcome after the incomplete render of 18 hs ...and 143 samples

[DriesV]

First of all, look at my comment in your original topic.

Secondly, it looks like you are rendering with NURBS. It is not uncommon that rendering with NURBS is five times slower.

Thirdly, your final rendering resolution (2560 x 1600) is significantly higher than the real-time resolution (1526 x 954). A high resolution image will look better than a low resolution image for the same amount of samples.
Also, remember that doubling the resolution (in width or height) quadruples the amount of pixels, and thus also quadruples the rendering time.

Dries

[zooropa]

First of all, look at my comment in your original topic.

Secondly, it looks like you are rendering with NURBS. It is not uncommon that rendering with NURBS is five times slower.

Thirdly, your final rendering resolution (2560 x 1600) is significantly higher than the real-time resolution (1526 x 954). A high resolution image will look better than a low resolution image for the same amount of samples.
Also, remember that doubling the resolution (in width or height) quadruples the amount of pixels, and thus also quadruples the rendering time.

Dries

1. Answered and many thanks
2. I am aware of this, I did not know was 5 times slower, but I could see how the image went quite lower in FPS.
3. Ok did not know  that as same amount of samples a the higher resolution will look better. This makes me rethink the ideal final samples for my scene. I might not need to many then.

Thanks so much , apparently nothing weird with KS then.


Regards

[TGS808]

143 samples ...in 18 hs is not possible

When I tried to finish the render asked me if I wanted to stop it...so for KS was not finished.

I am a little bit confused about what is happening. Is it a bug ? Did the render finished and KS was not understanding it was finish ?

This is all normal.

You never told us what your setting for max samples was. Judging from your screen shot it must have been super high. Look at the blue progress bar at the bottom right corner of your rendering. It's only at 11% after 18 hours. That indicates that it is not done (not even close). Or at the very least, it has not reached the max sample rate that you set it to. (which is why KeyShot asked you if you wanted to stop and save) If you don't stop it, it'll keep rendering until it hits the number of max samples you set (which could have been days from now). At that point the progress bar will read 100% and KeyShot will give you the green check mark in the top left corner. Often–as you've just experienced–your rendering can look great before it reaches the sample rate you set.  That KeyShot lets you stop and save rather than wait until it's "done" to get your final image is a nice feature.

In the future you should make use of the region render tool in conjunction with the heads up display ("H" key on your keyboard). Choose a tough area of your scene and isolate it with the region tool. Use the heads up display to see how may samples it takes to get the area looking as good as you want/need it to be. Once you have that number, use it as your max sample setting. Doing that will ensure your scene will look good at any resolution.  Keep in mind though that the bigger your image resolution is, the more the time is going to increase for the render.  For example: if you have a scene set to  600 x 600 at 200 samples it will render a lot faster than the exact same scene set to 6000 x 6000 at 200 samples. The outcome will be the same but the bigger one will look better as you'll be able to see more details clearly.

[zooropa]

143 samples ...in 18 hs is not possible

When I tried to finish the render asked me if I wanted to stop it...so for KS was not finished.

I am a little bit confused about what is happening. Is it a bug ? Did the render finished and KS was not understanding it was finish ?

This is all normal.

You never told us what your setting for max samples was. Judging from your screen shot it must have been super high. Look at the blue progress bar at the bottom right corner of your rendering. It's only at 11% after 18 hours. That indicates that it is not done (not even close). Or at the very least, it has not reached the max sample rate that you set it to. (which is why KeyShot asked you if you wanted to stop and save) If you don't stop it, it'll keep rendering until it hits the number of max samples you set (which could have been days from now). At that point the progress bar will read 100% and KeyShot will give you the green check mark in the top left corner. Often–as you've just experienced–your rendering can look great before it reaches the sample rate you set.  That KeyShot lets you stop and save rather than wait until it's "done" to get your final image is a nice feature.

In the future you should make use of the region render tool in conjunction with the heads up display ("H" key on your keyboard). Choose a tough area of your scene and isolate it with the region tool. Use the heads up display to see how may samples it takes to get the area looking as good as you want/need it to be. Once you have that number, use it as your max sample setting. Doing that will ensure your scene will look good at any resolution.  Keep in mind though that the bigger your image resolution is, the more the time is going to increase for the render.  For example: if you have a scene set to  600 x 600 at 200 samples it will render a lot faster than the exact same scene set to 6000 x 6000 at 200 samples. The outcome will be the same but the bigger one will look better as you'll be able to see more details clearly.

I am sorry if I expressed wrong. I was not intending to complain about how a progress bar works. I understand was not finish. The point was if  something I could do or I was doing wrong to make it more efficient in time.

There is a point you wrote which is interesting and I did not know. The amount of samples will influence the sample number 140 ?
For example, if I set up my render to 140 samples ....as a final max sampling...will it make it faster than the one where I set it to 1200 samples by the time it gets to the 140 samples ? That I honestly did not know...and explains a lot.

Thanks a lot man!

[Will Gibbons]

For example, if I set up my render to 140 samples ....as a final max sampling...will it make it faster than the one where I set it to 1200 samples by the time it gets to the 140 samples ? That I honestly did not know...and explains a lot.

Sorry, but this is not correct.

Let's say I have one scene and I render at 64 max samples and it takes 5 minutes.
Then, I render the same exact scene at 6400 max samples. After 5 minutes, it will have rendered 64 samples.

Sample number does not affect render speed, but render duration. Unless my tests are wrong or if this does happen on very complex scenes, you should experience no difference by by increasing the samples count.

[TGS808]

I think zooropa may have misunderstood what I was saying. The example I gave is something I've experienced many times. I use the region tool on a tough section of my scene and (using the heads up display) I determine how many samples it'll take to get that area to look good. Once I have that number–lets say it's 200 samples–I set the max samples to 200 as I know I won't need to go any higher for a good looking image.  If I render that image at 600 x 600 it reaches that 200 much faster than if I set the exact same scene to render at 6000 x 6000. The bigger image takes more time even though the sample rate is the same. I suggested the region tool/heads up display technique (I'm sure I'm not the only one who does this) as a way to zero in on a sample amount that gets the job done rather than just blindly turning it up high to try to get a good result.

[zooropa]

I think zooropa may have misunderstood what I was saying. The example I gave is something I've experienced many times. I use the region tool on a tough section of my scene and (using the heads up display) I determine how many samples it'll take to get that area to look good. Once I have that number–lets say it's 200 samples–I set the max samples to 200 as I know I won't need to go any higher for a good looking image.  If I render that image at 600 x 600 it reaches that 200 much faster than if I set the exact same scene to render at 6000 x 6000. The bigger image takes more time even though the sample rate is the same. I suggested the region tool/heads up display technique (I'm sure I'm not the only one who does this) as a way to zero in on a sample amount that gets the job done rather than just blindly turning it up high to try to get a good result.

I think we are talking about different things. You are giving an advice/tip which is quite understandable and make sense. Use region render to determine the quality/sample ratio and thene apply that to the final render setting. That I believe it is clear and understandable, and yes, other people work like that too.

I started the topic with the intention to understand if something was wrong in my scene. Please notice that regardless of the region render technique you are pointing out, the scene takes 18 hs to render 140 samples. That was my point. I do believe I explained wrong. And yes, of course, by making a render region I understand I will get to 140 samples...faster than render the whole scenario. Thanks so much I am trying to clarify. In any case the slowness comes from my model in Rhino...

[TGS808]

Hey, it's cool. I may have misunderstood too. We're all here just trying to help each other out. If it was your model causing the problem no advice any of us could give was gonna help. But at least you were able to get to that conclusion.

[zooropa]

Hey, it's cool. I may have misunderstood too. We're all here just trying to help each other out. If it was your model causing the problem no advice any of us could give was gonna help. But at least you were able to get to that conclusion.

of course man, I can not say more than thanks to you and all the people willing to involve.