Meeting a crazy deadline (please help!)

[cyrillweiss]

if you need some GPU Power, I can help you out, just send me your octane file + OBJ + texture files. If you have more than one camera perspectives, send me for each camera the scene file.

Best regards
Cyrill

[matej]

The spots you see are supposed to be halogen "stars" on the ceiling... it's a client idea and I agree they sould maybe be a bit less bright....

I thought they were fireflies, sorry. All those emitters in your first scene are a bit overblown, so you should tone them down and try to find the right lighting also with imager settings (gamma & response curve), as remon_v said.

But since you have so many tiny light sources, noise (=slowness) is granted. Such scenes as the one in your first post are particularly slow to render with pathtracer algorithms. PMC is just an optimized pathtracer and the only option for this particular scene of yours. It will still be slow, though.

I don't have much experience with interiors, so maybe someone else will share their PMC techniques to battle this problem. (but you can forget about rendering 5 final shots in 5 hours)

[acc24ex]

yes, you have the worst case scenario right there - tiny lights, reflective surfaces - this is a 1 render per night scene -
- other way is to break off walls try to do it in directlight - and fake your way through -
- interiors are still a pain to render, there was some news on a new render kernel optimized for interiors, hope it will help in the future

.. now you can set the samples of the emitters - what I read was to lower the samples for the lights that are too far away - should do something with the noise issue - those small lights are going to add to noise for sure
- and I guess you deadline is up -

[enealefons]

Guys, I'm so thankful for your interest and your help!
I managed to nudge forward the deadline by 10 more hours... so... the light of hope is lit up again

I am moving forward with the night shots; rendertime is still unbeareable... but I'm sort of enjoying this fast learning pushed by stress.

I have a couple of questions:

- What does sampling_rate do? with so many lights I guess tweaking it could bring to some improvements, but I don't seem to understand the logic with which it operates: all my lights are around 80, and I needed to put the lamps at 100 samples in order to have some light shine through.

- As you can see, after tweaking the light by inputing the correct WATT (e.g. 20w = 20.000), the only way to see something in my scene is to keep fstop at 1 and ISO at 800... but I smell something wrong here: in the real world one would use such a setting in almost total absence of light, and I should have plenty! I noticed however that with certain camera response presets this doesn't apply... I'm confused

- I was expecting a different behavior from the lamps: I expected the light to lit the area beneath the lamps "like spotlights"... but now it looks like it's just filling the whole environment... is this behavior normal?

Thank you SO MUCH for your support, it's really appreciated!

[enealefons]

@acc24ex - I tried everything with directlighting; unfortunately it won't resolve correctly all the light sources, especially the neons around the ceiling of the room... the only one which got close was the diffuse(4) mode... which ended up being somewhat noisier and SLOWER than PMC.... also, thank you for the hint on the samples: unfortunately for practical purposes, I'm controlling all the lightbulbs with a single emitter material, also all the stars on the ceiling are controlled by a single material, I'll try later to reduce the samples for the "stars"!

@Matej - indeed!

@cyrillweiss - THANK YOU so MUCH! At the moment I'm still tweaking the scene (to me it still looks horrible), but wow, I really appreciate your availability, I'll keep you posted on the developments!

@Remon and @reppet - Thank you!

[enealefons]

Question: is there a way to use Octane's tonemap on an OpenEXR without rerendering? No, right?

[roeland]

You indeed can't load an openEXR rendering again for tone mapping.

If you have a mix of perfect specular and diffuse surfaces, you can increase caustic blur in the kernel settings, for a start try 0.1. This will reduce the precision of caustics in the scene but it will produce a render with less noise.

I would also recommend using PMC for a scene with lots of light sources. Most of the settings can be left at the defaults. For scenes with lots of light sources increasing direct_light_importance may improve the noise.

The sample_rate parameter in light sources can be used to override the way Octane distributes calculation effort between the light sources. Octane will by default use the power emitted by the light sources as weights. If all your light sources are inside the room these can probably be left at 1.0.

--
Roeland

[enealefons]

Hi Roeland!
Thank you for the suggestions!

What an adventure: I don't regret having embarked the Octane ship for such an important delivery with such a tight deadline... but it's proving to be more complex than I expected: this is really my first approach to Octane at all, I come from Mental Ray / Renderman so there are many things still for me to grasp about Octane.

I got an important question which might clear my mind:

In order to achieve photorealism, how should I arrange my workflow?

Once I have my scene setted up, in the right scale, what comes first in order to be able to check the results and expect them to be coherent?

Should I proceed by setting the lights first (following the proper watts and temperature), and then on to the materials... or viceversa?

In the current scene it just happened to me that I seem to obtain the light behavior I wish by over-brightening my light sources. for example, the lights you see in the following renders should be 100W, but I can start to see some distinct light bleeding on the adjacent furniture only if I crank the light up to 300W.

By that, I obtain the wanted light-bleeding... but the light-screens just turn white.

Should I expect the camera and light settings to behave au-pair with the real world settings... or should I simply aim for the best picture from the beginning?

I am having lots of fun though

[enealefons]

Dearest all,
Happy ending I guess!
After a full day of work I managed to come up with something acceptable.
Average Rendertime is 20 minutes, in directlight_AO, filtered with Neat Image to eliminate the noise.

However, the quest to master Octane and understand how to deal with interior nighttime renderings in acceptable rendertimes and foreseeable result is still on... I'm so thankful for this wonderful software and I'm really glad to enter this community of great render artists.

All the best,

Enea

[enealefons]

aaaand this!