[CodyKallas]

Wow, looks like I opened a can of worms. Looks like a lot of learning being done though so thats good. I haven't been on very often, working on other projects. For the animation I will be retexturing and rendering with modo. My camera moves are swooping in and out of this large interior so it sounded like the stuff discussed with hdri and 360 renders won't work too well. The animation will be about 2 minutes long at 30 fps so even if I get the frames to 1 hour a piece that would still cost a ton to send to a farm. I can get it down with modo, no big deal. That is the glory of having a few options. And I probably should have known, but haven't been able to experiment too much, hdris are that much faster? I will try to work them more and more into my workflow. I thought emitters were faster... But that is just me going off of what I read online, maybe I got confused along the way?

And for stills, these speed increase suggestions are nice, and I also try to make things go as fast as possible, but it is always a plus to quote out sending it to a render farm and clients are starting to understand the time it takes to render these things. Or I have a mini render farm, just 5 nodes that speed things up as well. So if you have the money, you can kind of be a little more loose on your rendering options.

I am more than willing to try some of these suggestions though, but I have been busy. I really appreciate everyones insight on this.

Thanks

Cody

[photomg1]

test 2,

removed hdri emitter now using original global hdri only




gives result below , which is very fast but has no bearing on original scene lighting . Although absolutely perfect if I remove all the walls and want to use it in the way Egmehl did.



next try was brightening the windows area by four stops on the hdri , lighting has more contrast but is not similar to the original lighting.The more the contrast is going up in the hdri noise is back in this timescale.






Final variant , original scene hdri comped back ontop of the room hdri windows to try and get back the true lighting.



original lighting has not returned , and the image now is much noiser and returning in appearance to the image using an emitter hdri plane





Conclusion so far I cant get any speed up by removing walls and ceilings whilst using hdri images .If I'm trying to replicate original lighting setup . The only image that displayed a real speed increase, from a lighting perspective looked nothing like the original (first large image on this post).

Clean reference lighting image below (I used modo (30 mins) for this one hence missing reflected caustic off the chair).





So I still seem to be going wrong somewhere on treating the set like a tv set using hdri's . Any ideas where I'm going wrong ? or does this only work ( speed up ) when just using pure emitters and no hdri's/enviroment which is what I'm beginning to suspect after 2/3 of a day testing this.

[Mihai]

Can you send me this scene privately? It would be interesting to test a few things with it.

[photomg1]

Hi Mihai ,
It will be tomorrow afternoon now I' m out of my office in the morning. Which version would you like ? The original version with the outside hdri or the version with just two walls and the interior hdri.

Mihai, I genuinely do appreciate the support you are giving on this btw . Many thanks for that.

I'm definitely hoping I'm making a glaring error that you are going to point out to me .

Best

[Mihai]

There is no guarantee of that I do also appreciate that you did these tests, which took some time obviously. I'm not saying this is a 100% thing that can work in all cases, and there are two things here which make it less efficient in your case: one is that mixing emitters with other kinds of lighting will make Maxwell prioritize the emitters and so you get back more noise from the HDR lighting. If you had a case where more overcast lighting was enough, then you wouldn't need the extra emitter and it would be much faster. The other reason is that this isn't a very complex and larger interior, so the gains are also less visible because of that.

[Mihai]

Sorry, forgot to mention which version, the original version with all walls and HDR outside.

[photomg1]

Hi Mihai ,
Hopefully you should have received a link to the folder sent to your nextlimit email . I did keep this test scene as simple as possible just to see what was going on with the options .At some point I might test this procedure again on a larger more complex scene.

Thanks again

Matt

[photomg1]

Have you had a chance to look at it yet Mihai ??

best

Matt

[Mihai]

Sorry for the late reply Matt.....

So I think what matters here to get back that contrast you mentioned is how you tweak the resulting room HDR, and trying to stick with only one type of emitters. Of course it won't be really possible to match EXACTLY the lighting with the real actual room, and this case doesn't really show how big the benefits can be (room is pretty simple and small with large window), plus this method would also be more suited for situations where the lighting is flatter (just saves you to tweak the resulting HDR).

To tweak the room HDR I copy pasted the brightest part of your sky HDR over the windows, and using a mask, made it so it covers the windows, pretty similar to what you did. Except I also used an exposure adjustment layer and lowered the exposure by about 3 stops I think for the rest of the room and using a mask again to make this adjustment layer not affect the bright part I pasted.

Here are two renders, one is the scene you sent me, just rendered it for 15 min. The other is with two of the walls removed and my HDR, also 15min. You can see there is substantially less noise and I'm guessing it would take the full room version at least 3x longer to get as clean.

I was concentrating mostly on getting the same amount of contrast in the shadows and light falling on the wall. If you compare with the full room version of course you will see differences, but if you only imagine you saw the removed walls version would it be so bad?



This is the tweaked HDR in psd format:
https://www.dropbox.com/s/e0y4j8ls8x0xp9w/testHDR3.rar

[Mihai]

Rendered the full room version for 60min (so that's 4x longer than the removed walls version) and you can see there is still more noise in the indirect light areas, which will take the most to clear.

[photomg1]

Great stuff Mihai !

thank you very much for looking into it , I'll study your file today.

best

Matt

[eric nixon]

Its frustrating reading this thread. The problem lies with the fact that hdr's are an infinite sphere, and the room walls are not infinitely large. So the lighting they produce is different (look at the lighting on the seat of the chair). But you can make this technique work better by creating proxy walls which are simple plane emitters with the hdr mapped onto them.

[Mihai]

Well if you mix HDR lighting with real emitters again then you have two types of lighting and becomes less efficient. I'm not really trying to recreate the exact same lighting as if the entire room was there, but it's pretty close and at the very least you get 4-5x faster renders it seems. Especially if you have an animation, it's worth considering it.

[eric nixon]

Ah yes I see. I guess if you have a static camera it could be worth considering otherwise the lighting will look very odd I think... and then also perhaps just render the figures and the floor, and comp or use a screenmap (render of wall + picture frame in this case).

[CodyKallas]

I am glad I started this thread, learned a lot. I need to start implementing these techniques. To speed up renders. I still feel like I am missing something. I find it extremely difficult to get an interior without noise. Even at something like sl20 I will still have noise. Where as if I can get it to like 22, I am fine. I am trying really hard to not use the environment and just use emitters.

I have read the lighting interiors optimization tips a million times. So I am trying to light with only emitters but I am having troubles. But most of my renders have been HUGE rooms with like 20 light sources, or I will have glass, although I use AGS. I did a frosted glass render that took awhile.

Just overall, I know these techniques are out there, I just need to figure how to do them. Like this HDR trick for example, never have done it, but it looks like it could help times...

Is there any list, or anyone could make a really solid list of what to try and do and what not to do for interiors. I have read all the documentation on this, several times, but still feel like I am missing something.