Hot Pixels...

[bpzen]

Ok, I really need to knwo if this render engine can do indoor renders when there is Spec materials involved. I have tried to reduce mesh lights (black bodie) to as low as 1 and crank up exposure very high, but if i have a figure in the scene with gold metal arm bands or carrying a steal sward I get crap results hotpixes all over near the metals and lots of noise even after 20k passes...

This in a room with 4 walls a floor and a ceiling no HDRI no environment. I take the walls down and use HDRI or Sun and the iamges look fine (with out the lighting/shadows) I want - its way to flat with HDRI and in a room I cant use sun light etc.... This is really frustrating, is Octane just not a good engine to use if I need to leverage mesh lighting?

Using HotPix removal slider makes the iamge look blury if i go were i need to in order to remove this.

thanks for any advice..

[Sorel]

One thing that helps is to turn caustic blur all the way up to 1 in the render settings. If you really want the caustics to be more visible though, I'm not sure what other advice to give. I get wonky results with meshlights myself. Something else that might help is to give the lights an IES profile. I have done this for a few interior scenes and it seemed to help.

[face_off]

Reduce GI Clamp - as recommended in the Octane Notes link in my signature below.

Paul

[TRRazor]

All methods previously suggested are meant to take care of the symptoms, but never really cure the actual problem most users have with photometric lighting.
Try to light the room REALLY brightly and very evenly, don't leave a single spot unlit.

Then, use the exposure to achieve the light mood you want in the room. (By lowering the value you'll get darker moods, by setting it higher, you'll get brighter moods.).

I come from a photography background - the method described above is the same movie sets are lit - try it, you'll see, it works and it will get rid of that nasty specular noise
When done right, you'll never ever need Hotpixel removal, GI clamp and or caustic blur EVER again.

Remember: Hot pixels in a room only appear, when there is not enough lighting information for the renderer to return!

[bepeg4d]

Ok, I really need to knwo if this render engine can do indoor renders when there is Spec materials involved. I have tried to reduce mesh lights (black bodie) to as low as 1 and crank up exposure very high, but if i have a figure in the scene with gold metal arm bands or carrying a steal sward I get crap results hotpixes all over near the metals and lots of noise even after 20k passes...

This in a room with 4 walls a floor and a ceiling no HDRI no environment. I take the walls down and use HDRI or Sun and the iamges look fine (with out the lighting/shadows) I want - its way to flat with HDRI and in a room I cant use sun light etc.... This is really frustrating, is Octane just not a good engine to use if I need to leverage mesh lighting?

Using HotPix removal slider makes the iamge look blury if i go were i need to in order to remove this.

thanks for any advice..

hi,
please, could you post a couple of screenshots about the issue and your scene settings?
Are you using mesh emitters to lighting the scene?
And how they are modelled and placed in the scene?
Different languages and different terminology could bring confusion, so it's always better to see some images to better figure out what's going on
ciao beppe

[DrHemulen]

That is extremely interesting TRRazor. I just assumed that there was to MUCH light for the renderer in those spots. That's definitely something to play around with.

[TRRazor]

That is extremely interesting TRRazor. I just assumed that there was to MUCH light for the renderer in those spots. That's definitely something to play around with.

That's how it works though - kind of paradox, I know.
The OctaneRender camera works pretty much the same as the film material rolling inside a movie camera, the higher you crank up the lights, the lower you can go with your ISO, which results in lesser visible noise in your image - sound familiar?

Same thing applies to scene lighting in Octane. Light your scene nice and even and you will never again have a problem with render noise again.

When you notice visible noise in movies, you know that the director of photography wasn't doing his job right in picking the right film material and/or lighting the scene correctly.
Check out Michael Mann's "Collateral". The movie was shot mostly with available light, which meant the DOP had to really crank up the ISO resulting in heavy noise in most scenes. This is particularly noticeable on the BluRay, due to the high resolution of the source.

Just did a quick YouTube search for some examples: This sums it up pretty well actually, although the light sources picked in this example were pretty terrible. Looks like the guys were working on a tight budget.

[Notiusweb]

I had this exact thing happen to me. Here is my example. I posted this in the main OcDS forum a couple days back (not to show Paul an example of a bug, but as a gesture towards being excited about Version 3...)

Check the 3, that is reflection of sunlight causing the pixelation. It would not unpixelate no matter how long I rendered for (24K samples...thats 24 Kazillion). It was a shame, because I could not land the effect I wanted. I used post processing to sort of cover up, but you could still see pixelation.
It wasn't a mood shot or anything, just glitz and glare. Outside of Photoshopping it I don't think there really was a way to mod it via dimming and achieve the same effect.

[Spectralis]

That is extremely interesting TRRazor. I just assumed that there was to MUCH light for the renderer in those spots. That's definitely something to play around with.

That's how it works though - kind of paradox, I know.
The OctaneRender camera works pretty much the same as the film material rolling inside a movie camera, the higher you crank up the lights, the lower you can go with your ISO, which results in lesser visible noise in your image - sound familiar?

Same thing applies to scene lighting in Octane. Light your scene nice and even and you will never again have a problem with render noise again.

When you notice visible noise in movies, you know that the director of photography wasn't doing his job right in picking the right film material and/or lighting the scene correctly.
Check out Michael Mann's "Collateral". The movie was shot mostly with available light, which meant the DOP had to really crank up the ISO resulting in heavy noise in most scenes. This is particularly noticeable on the BluRay, due to the high resolution of the source.

Just did a quick YouTube search for some examples: This sums it up pretty well actually, although the light sources picked in this example were pretty terrible. Looks like the guys were working on a tight budget.

How does this work with spot lighting where the scene is lit in a few places to create a noir look? Is it correct in OcDS scenes to light the scene brightly all over and then light specific areas even brighter with spots and then lower the ISO to darken the scene down? The video example you posted uses various LED's to light up specific areas of a dark scene but trying to use OcDS emitters in this way often creates a lot of hot pixelation.

[bpzen]

Thanks all, I am going to give TRazors approach a shot and ill post some examples, the issues are for sure metal / spec rings , necklaces and brackets on the characters. I have a "reflection" / hot pixel spots/specs or something all over the under side of the characters chin for example ( I have tried reducing the emitters to .01 and still happens or up to 40,60, 100 wats... juts not dealing with spec mats very well.

I use a simple 3 point lighting set in a room with walls and floor and ceiling, I am not using HDRI or sun - using that everything looks fine but not reflective and sorta flat to me. Id rather use mesh or texture lights I feel it looks better with occasional fill light using hdri or sun with windows involved.

I am creating primitive Spheres for all 3 point lights changing opacity helps some but there goes any eye reflection of gleen on skin etc....

Its really frustrating, I dont think this is a plug in its the main Octane engine for sure but I cant imagine why the devs would not address this with out having to blur out an image.

Again ill give the suggestions a try up top thanks.