Same settings different results

Lal-O · Post by **Lal-O** » Tue Jan 03, 2017 4:43 pm

Hi guys .
I have a question ... Why do i get different results from a scene ( with the same settings ,lights , camera ,geometry etc.etc .) if i change the rendering mode?
If i use CPU+GPU i get darker joints and brighter renderings...Is that normal?

In some cases the dark joints seem to be a bad modeling problem.
Everything is fine only with CPU.

Thx in advance.

Zom-B · Post by **Zom-B** » Thu Jan 05, 2017 12:40 am

Yes, I reported a quite similar issue back in 4.0.15 to the devs, I tested the example scene I provided back in the day and can reproduce the problem:

: left CPU - right GPU

Lal-O wrote:If i use CPU+GPU...

In your case you only render with the Titan X card, no CPU involved here

Post by **Oscar J** » Thu Jan 05, 2017 12:43 am

Lal-O wrote:Hi guys .
I have a question ... Why do i get different results from a scene ( with the same settings ,lights , camera ,geometry etc.etc .) if i change the rendering mode?
If i use CPU+GPU i get darker joints and brighter renderings...Is that normal? In some cases the dark joints seem to be a bad modeling problem.
Everything is fine only with CPU.

Thx in advance.

While it's weird that the brighness is different, I kinda like the GPU render better.

pixie · Post by **pixie** » Thu Jan 05, 2017 1:40 am

Oscar J wrote:While it's weird that the brighness is different, I kinda like the GPU render better.

GPU makes everything better!

Lal-O · Post by **Lal-O** » Thu Jan 05, 2017 4:17 am

Zom-B wrote:Yes, I reported a quite similar issue back in 4.0.15 to the devs, I tested the example scene I provided back in the day and can reproduce the problem:

The attachment darkening.jpg is no longer available

Lal-O wrote:If i use CPU+GPU...
In your case you only render with the Titan X card, no CPU involved here

Yeah but as long as i know the goal of using both (CPU+GPU) is getting faster rendering times, right? Most of times my deadlines are really short so i think that disabling any of them is not an option to me

....just a tought

Here is another example of a " bug " in the joints with CPU+GPU

I can deal with brightness variation in the images, but the "light" through some joints i think is a problem

Post by **Oscar J** » Thu Jan 05, 2017 4:21 am

Does look like some sort of precision issue.

Eneen · Post by **Eneen** » Thu Jan 05, 2017 4:36 am

Maybe obcjects have their origin far from geometry?

Lal-O · Post by **Lal-O** » Thu Jan 05, 2017 4:43 am

Oscar J wrote:Does look like some sort of precision issue.

Yes it does look like, but the model is really well done, i can assure you that

Post by **Oscar J** » Thu Jan 05, 2017 4:45 am

Yeah I meant an Indigo precision issue.

Eneen · Post by **Eneen** » Thu Jan 05, 2017 4:52 am

Does adding floor cap at the bottom fix it?

Lal-O · Post by **Lal-O** » Thu Jan 05, 2017 4:59 am

Oscar J wrote:Yeah I meant an Indigo precision issue.

Ooooohh i see... Yes , it seems so

Lal-O · Post by **Lal-O** » Thu Jan 05, 2017 5:03 am

Eneen wrote:Does adding floor cap at the bottom fix it?

I tried with and without the floor cap and no luck. Only CPU and problem solved

Zom-B · Post by **Zom-B** » Thu Jan 05, 2017 6:01 am

Lal-O wrote:Yeah but as long as i know the goal of using both (CPU+GPU) is getting faster rendering times, right? Most of times my deadlines are really short so i think that disabling any of them is not an option to me ....just a tought

still you are not rendering with you CPU in GPU mode mate, believe me!

You have no openCL drivers for your CPU installed, otherwise your CPU would be in the OpenCL device list, doublecheck CPU usage during rendering when your Titan card is active and you'll see!
It should look more like that:

: CPU.PNG (10.46 KiB) Viewed 4322 times

Zom-B · Post by **Zom-B** » Thu Jan 05, 2017 6:02 am

Lal-O wrote:I tried with and without the floor cap and no luck. Only CPU and problem solved

Maybe you could copy these few elements in a new scene and upload it, so the devs have some reduced scene to test while fixing it

Lal-O · Post by **Lal-O** » Thu Jan 05, 2017 6:29 am

Zom-B wrote:
Lal-O wrote:Yeah but as long as i know the goal of using both (CPU+GPU) is getting faster rendering times, right? Most of times my deadlines are really short so i think that disabling any of them is not an option to me ....just a tought
still you are not rendering with you CPU in GPU mode mate, believe me!

You have no openCL drivers for your CPU installed, otherwise your CPU would be in the OpenCL device list, doublecheck CPU usage during rendering when your Titan card is active and you'll see!
It should look more like that:

CPU.PNG

OH MY GOD!!!... I've been living a lie!!!...I've always thought that by simply checking on the OPENCL feature i was able to render with CPU and GPU at same time. I feel so dumb

.
Would you please tell me what do i need to do to get my CPU shows up in the device selection? Is an Intel I7 5960X. I would really apreciate your help

Same settings different results

Same settings different results

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Re: Same settings different results

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Re: Same settings different results

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Re: Same settings different results

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