First off I want to say a massive thank you to joconnell, what a fantastic run through of your theory that we first talked about in the ‘understanding dmc’ thread, it is a powerful technique for rectifying pesky noise. However I still can’t seem to get this theory working at production level.
I’ve been running through the steps again on a fresh interior scene animation and still hit the same problems of unacceptable render times; to get a nice smooth raw lighting pass I’m up to 512 subdivs on my dome light - a Peter Guthrie HDRI - which sends my times through the roof and isn’t workable on a live job. I then revert back to my old ways and ‘store with irradiance map’ on the dome light which gives low render times but blotchy GI. Upping imap settings to 100/35 cleans it up but still not ideal.
So I have perfect quality render passes but 13hrs per frame at 1024 x 576 (!!!) or decent passes and just about acceptable blotchy gi with 14 mins per frame. Where’s the happy medium?? Does it even exist? I can live with ‘store with’ on my dome light if I can get the render looking sharp but I feel the imap settings are making it look ‘mucky’.
Excellent video full of great tips and info! I also love that you did not just glaze over the problems and how you solved them step by step.
It was a nice change since many videos seem to “over-summarize.”
Anyway, thanks so much for making it and for free, too.
Best regards and thanks!
Hmm, might be a better idea to downres the HDRI quite a bit? With a lot of the sIBL sets they supply one hdri for reflections at full res, a lower res one to drive lighting and often a light rig where any strong light sources are painted out of the hdri and replaces with actual vray lights with a similar light multiplier and colour.
on a side note, I had coplanar faces in that first test, sorting that out plus using the (superb) reinhard trick got the render time down to 3.5hrs, still stupid but a fair bit better than 13hrs!!
Yep - big improvement alright! The Reinhard one admittedly does lose some dynamic range in the image but nothing that can’t be added back in with a slight bit of levels or curves in photoshop afterwards.
Massive thank you to you Jon as well to Toni and Akin for all of the contribution to the 3d industry. Vlado can we have this as sticky or even documented into the manual sometime.
More to come Alex, I’ve gotten some good feedback from viewers so I’ll make some adjustments. There’s all the major improvements in vray 3 to come in and other artists are constantly testing and finding new ways to speed things up - exciting times!
Sounds good. I actually tried your method(s) out on a scene yesterday and managed to bring my rendertime down for a complex interior from around 5hrs to just over 3 and it looked perfectly fine. I need to look more into this balance between high light and material samples and lower AA. This is a very tricky and complicated balance it seems.
Sure. My method isn’t necessarily the only one either, a very smart user called Emanuelle Lecchi is constantly looking at various other methods to simplify this, hopefully he’ll publish something very soon!
Cheers Steve! The general feedback is that it’s not quite as accessible as Akin’s or Grant’s very bloody good tutorials which is totally fair, it’s not designed to be that. What would you like to see if I was to expand on it though?
Stuff like this is amazingly useful, but would like to see something that uses heavy geometery, a much larger scene, foliage, trees etc. DOF.
This along with grants etc. are amazing for general technical approach, but once i start trying to apply it to the more mental scenes its starts to fall apart a little because Its not clear how to adapt the approach based on larger scenes & animations. For me the interior stuff never covers ‘real world’ situations. How does one tackle a shedload of plants, lots of glossy surfaces, DOF while still needing to render an animation in a reasonable time. (the current hell Im in)
Hey John,
Thanks for this great tutorial video. Been trying to break down a scene using the same technique for a fairly regular arch viz exterior scene that I lit with BF and light cache.
The scene is lit with a sun and vray dome light with a hdr in the dome.
I cleaned up the scene considerably by cleaning up the dome light select element increasing the subdivs to 128.
The only pass I had left to clean up was some noise in the Global illumination cause from the BF.
I increased the subdivs on the BF to 128 and it cleaned up the noise in the GI element but it made the Dome light select element noisier which has confused me all over again.
Ah okay! did you have the dome light clean with GI first turned off, then turn on GI, clean that up and find that the light pass was now noisy?
Could you pop up some of your passes and we can have a look? One thing that Vlado mentioned is when you have a dome light with GI turned off, all of the light contribution is direct light. As soon as you turn on indirect illumination though, half of the light comes from GI, half from direct. It’s the same amount of light shining on your object so the brightness won’t change at all, it’s just the way that it’s calculated will change a tiny bit.
The only difference between the noisy part at the top of the image and the cleaner bottom half of the image is that I changed the BF Gi subdivs from 32 to 128.
This of course will clean up the GI pass but it made my vray lighting pass noisier which really surprised me
Finished up on that contract so cant get access to the scene files.
There really wasnt that much going on in the scene. Building with exterior light i.e. a vray sun and a dome light with a hdri, brute force and light cache, the area we are looking at in the render is a vray mat with white in the colour swatch and nothing else.
Will try and recreate it in a simple scene later today.
The issue was rendered on vray 3 and the place Im working at right now uses vray 2. They are upgrading this weekend and will try and reproduce it next week.
