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Suppress small Artefact in PBR render


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@Dennis = "P.S.: I don't know why the first question (when it comes to performance) always seems to be whether you are using Windows or Linux. It might be true, that Linux is more efficient with memory management and that might be a big plus for simulations, but in general I have not found any relevant performance benefits in Linux. Especially not in terms of rendering speed (I tested this exhaustively). I am using CentOS at work and Windows at home."

 

I found that everything that is memory related you have a bit more benefit from Linux like you said, loading scenes, I found that also generating IFDs depending on your setup is also a bit faster I had an experience of seeing on certain cases up to 30% of difference of performance taking account off course things like time to load scenes, loading the geometry and textures on memory etc.., when it comes just to render yeah is very similar there are some cases that I saw even a little bit of edge on Windows but most of times in general I think IMHO that Linux is a better option for work with Houdini especially when you need to deal with huge amounts of data and you need to render them, but that's just me.

 

I am not even talking about network traffic performance where I also find a huge benefit from Linux if you have Windows, Mac and Linux in the same network but off course it depends on the studio setup.

 

It's really hard not to mention and ask about those choices because that's not a exact science there are a lot to consider and test, I would be glad to hear if someone would like to share experiences but since this is not the topic here maybe on another thread.

 

 

Cheers!

Edited by Mzigaib
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@Dennis = "Working with packed alembics in SOPs is a nightmare with big assets (5000+ packed primitives with a total of 20+ Mio. unpacked primitives). Assigning shaders with packed edits takes up to 5 Minutes to update because it seems Houdini is sending the whole geometry to the graphics card everytime instead of only the changes".

Yeah it does take time to update if you want to see it in viewport, which is a pain, off course but you can set to only display the non updated node and render the other, that I think can gain you some interactive time on viewport am I wrong?

 

@Dennis = "We are experimenting with material stylesheets right now and we'll see if that helps in regards to the shading workflow"

Please let us know how this goes.

 

@Dennis = "I would be happy for any suggestion in regards to the alembic workflow in Houdini as for us - in its current state - it seems utterly broken for any real production scenario."

Did you tried to use Mantra archive with Mantra delayed loader shader? Is a little bit more work to setup and you will probably need to cache more stuff but it is very efficient. Off course it depends of what you are doing.

 

I hope that some of it helps.

 

Cheers!

Edited by Mzigaib
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@sekow = " Imagine a toolset in which you could decide how to load content from abc's, dependent on rules and logic. Multithreaded traversing and and and.. some good times ahead of us."

 

I think you can build an otl that does that am I wrong?

 

Sorry by the number of posts I should have done that in just one place.

Edited by Mzigaib
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Hi

I am continuing with same light setup on other scenes

I wonder how to reduce noise in marked prob lem areas and whats causing this noise in dark areas

Impossible to see. Check the diagnostic image planes, you probably have to send more primary rays there.

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I would activate the following AOV.

- then check the direct diffuse / direct glossy / indirect diffuse / indirect glossy channel with Mplay buffer visualiser

- i think one of those channel must have a lot of noise you have to isolate where the problem come

- then when you have isolate the problematic channel check the number of sample

 

- i think the pb could come from indirect sampling because lighting sampling quality doesn't affect it

- the solution could be to enable indirect sampling check box and try something like min 4 / max 8 as a starting point

 

maybe it's something else ... :)

 

a zoom on the problematic area would be cool !

post-6698-0-59702300-1426195286_thumb.jp

Edited by sebkaine
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The HDR is missing in that file: turning off the GI light and substituting the Mandril for the HDR, adding Direct Shadows image- A Sampling Quality of the 'portalight' set to 0 & 3.5 has a direct influence on the quality of the shadow rays.

 

Please see screen grabs

post-8321-0-85129700-1426198088_thumb.pn

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Thanks ! i'm gonna check this. :)

 

I have also ask a prman 19 trial and here is a first test.

720P => 26min

- min sample : 1

- max sample : 128

- variance : 0.005

- integrator : path tracer

- light sample : 2

- bxdf sample : 2

- indirect sample : 2

- max diffuse : 2

- max specular : 2

- light shading rate : 10

 

prman_26min.jpg

 

i am not that impress.

 

the RIS is giving very nice accurate lighting result if you compare to maxwell and arnold. The speed looks to be on par with Arnold.

But RFM is still a really bad idea imo.

- now you have REYES / RIS that looks separate so if you shade your scene with reyes shader it looks that you can't switch to RIS

- lot of nodes in hypershade lots of option if you compare to Arnold and Maxwell ...

- RIS also looks to be the new workflow to adpot , but very few thing looks retro-compatible with reyes so prman is now a pathtracer

- basically RIS is a try to put some maxwell + arnold in renderman.

 

But i think it's like clarisse you need to test those engine on big scene with a need of flexibility to appreciate the power of the tool.

 

But Mantra again looks a better choice for me at the moment. Maybe i am mis-judging it , but RFM is really a mess especially if you compare to

Maxwell elegance and simplicity. Or Arnold very clean interface.

Edited by sebkaine
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Hi

I am continuing with same light setup on other scenes

I wonder how to reduce noise in marked prob lem areas and whats causing this noise in dark areas

 

This looks fixed by setting go the Noise Level lower and the Max Ray sSmples up. Please see screen shots.

post-8321-0-71056300-1426298167_thumb.pn

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in dt mantra tutorials they say that good guide for pbr samples is multiplying pixel samples to get number of max ray samples

so 6x6 is 36

 

 

Tutorials are good starting points, but you have to see if they agree with experiments.

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