grain in render

[mr-mégot]

hi,

 

I'm mr-mégot, I'm french, then sorry for my english...

 

I use cinema4d and I try fryrender for my render

 

I hope that you can help me, I use the demo, for the moment, of fryrender, and I have a problem with a render.

 

The render are a grain very visible on the wall of the apartement

 

the render are during 24 hours (in 800*600) with a dual core 2.2 ghz

 

Where come from the problem ??? It's the first time that I see a grain as visible ??

This is texture the problem ??

 

The picture are a tone mapping processing

 

I post also the preview of the wall texture

 

 

Thanks

 

mr-mégot

[Fran]

Hi Alexandre - welcome to CGA.

 

The sheer curtains in the window will cause the scene to take longer to clear. That is a low-light situation. It makes it a little hard to see what is going on there. But the wall texture looks like a good one.

[mr-mégot]

hi fran

 

thanks for the reply

 

I have make a tone mapping process for lighten the picture (increase power gain in master control, and light sun)

I hope that this help you

 

 

If I use a ghost glass for windows, is this hepl for reduce the render time ??

 

Thanks for your help

 

alex

[Fran]

Definately use ghost glass for windows.

[jorari71]

Hi...

 

I think it's a beautiful scene.

 

And the grain is not so visible...Better if it wasn't there, of course...But maybe if you take a photo in this room you probably obtain the same noise.

 

24h is a long time for FryRender.

 

I wolud say that images with Fryrender are made easily within 3 or 4 hours with a computer like yours. Well, always depend on the complexity of the geometry, if it creates a lot of rebounds of the beam lights.

 

I'm working in a scene (since I don't know when ) and I'm surprising how fast is FryRender in comparison with Maxwell. Of course with Maxwell the setting is much easier (I don't know why) but the rendering time is....SOoooo LOOOOoooooonnnnnnggggg...That you must have too much faith in the program.

 

One thing I miss in the RC version of Fryrender is something that makes possible the render of a region...This is a powerful tool that Maxwell has and Fryrender hasn't got. If a detail hasn't been well rendered you always can repeat the render inside this region and merge with a image retouch program like photoshop...

 

Soon I will show my image...Finally!!

 

Thanks for your advices Fran.

[Kurt]

I'm surprising how fast is FryRender in comparison with Maxwell. Of course with Maxwell the setting is much easier (I don't know why) but the rendering time is....SOoooo LOOOOoooooonnnnnnggggg...That you must have too much faith in the program.

 

Maybe a bit off topic (sorry) - but this makes me a bit curious. I've never seen a test that concludes that Fry is faster than Maxwell. I don't use Fry so I can't make the test myself. Can anyone confirm there is such a difference?

[jorari71]

Hi...

 

I'm a new user in un-biased render engines but due to an imposible scene for me to be made in vRay I was forced to llok a new tool, a new program in order to achieve my targets in terms of illumination and concretely Indirect Illumination.

 

I've only tested Maxwell and Fryrender and in the same scene I've realised that Fryrender was faster and maybe 2 times.

 

It's true that I've never achieved a full clean of noise image with any of both engines but the cleanliness was reached faster in Fryrender than Maxwell.

 

I read that in a MODO (Luxology) forum and not everybody affirmed that so clear but many of us started a serie of personal "tryings" I made that by myself and I found that this was true.

 

In another forum I found the same and many people say that the regular time for Fryrender is about 3 hours or so. I'd like to clarify that it depends on the complexy of the scene but by my own little experience the final results are visible at 30minutes and at the 3rd hour you can watch a non free noise image but really near to the final result.

 

But 24 hours with a Dual Core processor I think it's a bit expensive.

 

By other part if you try to reach an illumination with only Indirect light and through a glass the noise will be impostant after a few more hours. This is what I'm suffering with my scene. I will tell more details when I finish to render it.

 

Regards.

 

P.S.:Frances will help you more than I ...I'm only a beginner.

[Kurt]

Hi...

 

I'm a new user in un-biased render engines..

 

I've only tested Maxwell and Fryrender and in the same scene I've realised that Fryrender was faster and maybe 2 times.

 

With all respect jorari - I don't think that trying to render the same scene in the two render engines qualifies to draw a final conclusion about rendering speed. Okay - maybe a very experienced user might be able to do so (Frances?).

I have very little knowledge about Fry, but I know that I easily can setup a Maxwell scene to render 5 times faster just by doing some minor adjustments to light or materials - with no visible differences in the final result. I believe that the same can be achieved using Fry.

 

I have read everything I can find on different discussion forums comparing render engines, and it's not easy to find "unbiased discussions/conclusions" on this. Everyone seems to have their favorites...

[jorari71]

Hi...

 

Look at this:

http://forums.luxology.com/discussion/topic.aspx?id=27004&show=fryrender

 

What I know is that people who are talking in this thread are not begginers in Fryrender and Maxwell (like I am).

 

 

Regards...

[mr-mégot]

hello

 

thanks jorari.

 

in fact the render time for me it's not a problem. I have all the time

And my scene are certainely not optimize (the curtain are very heavy)

It's just that I think the grain are little too visible.

 

this week i make a new test with use ghost glass.

[Fran]

With all respect jorari - I don't think that trying to render the same scene in the two render engines qualifies to draw a final conclusion about rendering speed. Okay - maybe a very experienced user might be able to do so (Frances?).

I have very little knowledge about Fry, but I know that I easily can setup a Maxwell scene to render 5 times faster just by doing some minor adjustments to light or materials - with no visible differences in the final result. I believe that the same can be achieved using Fry.

 

I have read everything I can find on different discussion forums comparing render engines, and it's not easy to find "unbiased discussions/conclusions" on this. Everyone seems to have their favorites...

 

Kurt, Jose's opinion on render speed is based on his personal experience with the softwares and should be taken as such - an opinion.

[jorari71]

Yes Frances, you've got all the reason.

 

Regards.

[mr-mégot]

hello,

 

I think I have found the problem. It's the sconce. I have make a render without, and it's very better

 

When i use the 2 light of the sconce, the efficiency down at 76... without light, the efficiency are more to 250.... It's normal ??

 

the efficiency are a impact to the render time no ??

 

 

 

thanks

 

alex

[jorari71]

Remember anyway that you are illuminating through a glass and the render time will be longer.

 

Have you try using the ghost glass?

 

And another one: have you try using an opacity map for the curtains? Maybe this will be a better solution. I will try this last in a simplier scene and then you will suppose what happens in your complete scene.

 

The efficiency as Frances told us is a great indicator. You are right.

 

Regards.

[mr-mégot]

hi jorari

 

Have you try using the ghost glass?

yes

 

have you try using an opacity map for the curtains

yes with S5

 

it's not easy to understand

 

Here the test with no light (same time render)

 

i have only add s5 to the red curtain (but it's not very good aspect...)

 

Edited September 20, 2008 by mr-mégot

[jorari71]

I like the final result although both lamps added an interesting atmosphere to the final look of the scene.

 

But, it took 24h rendering time again? Well, the same time but less noise (grain) but without the two lamps.

 

Could you add chairs...Tables...More elements in order to fill the wide room? I think you could study the increment that it supposes in the rendering time.

 

Thank you for your contribution.

 

Regards.

[stormwind78]

Hi everybody.

The solution is quite simple... When you use Fryrender, you got to think like the Real physical render that it is.. So, imagine that you have a reflex camera on your hand, a low light scene and sudently when you adjust your camera diagram to get the amount of light that you need to get the perfect shot you notice that you have a high level grain on dark spots of the picture like shadow areas... That phenomenon is the same one that makes the diference between an ice cube and a snowflake.. if you freeze the water slowly, you get solid ice, if the water suffer a shocking low temperature, the water will freeze with "less quality" and the ice cristals become so big that you will have the so called Snow it self. With film nitrate (the one simulated by fryrender), happens the same. If you "burn" the picture too quickly, with a high sensibilization film ISO and you have a low light scene, the nitrate cristals will become so big that you will be able to spot them... if you have a iso so low that you need more exposure time to burn the same picture, those cristals will adapt them selfs becoming so little that you hardly can see them. Conclusion, low your film ISO level and raise your exposure time to get the best results for your shot. In real life you would need a tripod or else you get motion blur. Fortunaly, fryrender doesn�t simulate those error human movements...yet... I hope this was a helpfull reply to all those guys that get the same grain problem. Remember, if you abuse of a hight level definition image you will get something so perfect that is unreal. Every picture in real world is related with blur and grain, even if you zoom those pixels a lot.

 

Renderfull Regards.

 

Marco Calado.

 

P.S: I strongly recomend to anyone that loves photorealistic renderization, to learn everthing about photography since the early times of B&W Photo, will open your light horizons a lot wider.

[IceAged]

Interesting points, stormwind - however the noise phenomenon in Fry is not caused by the film speed, despite the simularities. Fry noise is a result of the light sources having to bounce multiple times before they reach the camera. A single light source hidden in a dark room, (eg, a concealed LED strip in a ceiling recess) will cause high noise levels; same if you took a photo of the real thing, but for different reasons.

[stormwind78]

Interesting points, stormwind - however the noise phenomenon in Fry is not caused by the film speed, despite the simularities. Fry noise is a result of the light sources having to bounce multiple times before they reach the camera. A single light source hidden in a dark room, (eg, a concealed LED strip in a ceiling recess) will cause high noise levels; same if you took a photo of the real thing, but for different reasons.

 

Your´re totally right iceaged. In fact, that´s another point a lot more usefull for this situation. To solve that, I´ll would try to simulate a soft light for this scene. A light located behind the camera with low level shadow, or any at all since we are dealing with simulated enviroments. Enough to catch shadows from the windows. High Closed Diagram and Low Film Speed will get you a good definition too, will focus the all scene.

[kroko]

So I have the same problem ... and I've tried a lot of way to fix it but ... nothink is helping Fryrender to get out the white spot in the scene!!!...

I'm following what you said ... and I hope it work, but I think it's a bug's Fry !!!...

My question is: ... can not be a modeling error ?!... or maybe I made some mistakes 3D modeling ... or maybe I missed a few tricks on the surface mapping and direction ...?

PS: I have some glass in the scene of course ... and try a "real" glass,...not a "ghost one"!

 

Ahhh some numerical suggestion for ISO film and Shutter speed?

Edited October 4, 2011 by kroko