Show Us Your Iray Renders. Part III
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Did a little experiment to put the "Normalizing Renderer" theory to a test. Raised each the Glossy Layered and Top Coat Weight on my skin setting by 0.3. Glossy Layered Weight now is at 0.95, and Top Coat Weight is at 0.65, making it a total of 1.6.
If the theory would be correct, the renderer would internally lower both Layer Weights by 0.3, so that the sum of them doesn't exceed 1.0.
In that case, both renders should look the same. As you can see below, that doesn't happen. The render with a total Layer Weight of 1.6 (Victoria@PixarCampus_9E#2) has way more gloss in it, and the coloring of the skin has changed, too.
If there is any normalization being done here, I'd expect it to do it by dividing by the sum of the weights, so here you'd have an effective glossy weight of 0.95/1.6 = 0.59375 and top coat weight of 0.65/1.6 = 0.40625. But I don't see why those two parameters would need to sum to 1 anyway to be physically correct, they're controlling separate layers of the material. I'm sure the renderer internally is keeping track of how much light is being transmitted by the top coat before reaching the glossy layer, we don't need to do that ourselves. (I didn't realize before you were talking about those two, I thought you meant things like controlling the amount of light reflected vs. diffused, which is automatically taken care of by any PBR renderer)
My approach for natural looking lips is to set them to the same glossy values as the rest of the skin. The default optimizer thingie makes them more glossy.
Having good bump/normal/displacement maps helps, too, so the lips have some texture to break up the shine.
(Unless, of course, you WANT lipstick, in which case don't do that much)
Thanks to all for the tips !
How would maps effect the whole normalization thing?
While this presentation is geared around the Unity game engine, it has some general information on PBR that is broken down and clarifies some aspects that might be confusing. Unite 2014 - Best Practices For Physically Based Content Creation (Not referring to the normalizing discussion, just a general post.)
The only normalizing so far I noticed was the overall exposure especially when a lot of object have reflective surface set on higher level, not the shader was normalized but the total render exposure in general .
I see Stefan right render changed where he have more specular on the skin.
I might be a bit biased in complimenting you but you did a really good job on the lighting. You make the car look really good.
Now try the interior! ;) Things light up in there.
Another set of presentations (each short) related to PBR but from a Blender perspective Physically Based Shading in Blender which also has some good breakdowns of some of the basic aspects of PBR.
Some of the main aspects I notice in various presentations is the concept of Albedo vs Diffuse, that PBR does not necessarily mean 'realistic' but rather consistency in different lighting environments, metallic vs specular, roughness vs more traditional concepts of glossy, and how much more important a good understanding of Fresnel is. Some of these many of us I'm sure already knew by now, but the Fresnel seems to be coming to the forefront much more in recent presentations.
Hi so this is my first Iray render, pretty simple, my video is a Nvidea GeForce gt 650M- 2GB (according to the sticker on my laptop) Core i5 win7 8GB memory. I have a few questions, I applied the iray shader to the entire car , then added different shaders to different areas like thin glass for the windows, cranberry car paint and white to the ar, but I applied the shiny rubber to the tires and a metal-nickel to the chrome but the tires ended up grey and the chrome is black, how do I correct these so they render properly?
Also I set the environment mode to dome and scene, draw dome on, and the ruins hdri in the environment map, how do I get a hdri ( like ones in the Yosemite set) to show up as a background in my render?
I have read a lot of the threads on iray but haven't found the help I need...they are very long!
The 8800GT won't use GPU and will default back to CPU. I have the 9800GTX and have this problem unfortunately. I upgraded to the 740 with 4GB ram and found it wasn't any faster then rendering with CPU (i5 760 @ 2.8ghz) so I returned it.
...the speed is governed by how many CUDA cores the unit has. the 740 has only 384 not much more than my old 460 with 336. Most of the units in the current 900 series have well above 1,000 with the 4GB 970 having 1,660 and 4GB 980 having 2048.
While there has been a delay both the 970 and 980 are to have the memory upgraded to 8 GB. Prices will probably be comparable to the current units as the Titan -X is priced about the same as the Titan Black (now "out of stock" at Newegg)
This is why I didn't consider the 740 even though it had 4GB memory.. Good you got your money back.
Is it possible to show a HDRI background applied to the Iray dome in the setup area? I want to rotate it to a certain point, but I have to keep guessing and rendering.
...restore the shader for the tyres, then when you click on the Iray shiny rubber shader, hold down the CTRL key. this will open a small dialogue that will give you the choice of replacing the current shader or ignoring it. clicking "ignore" should preserve the original shader, but give you all the Iray channels. ANdeasier option would just be to apply the baseIRyshader to the tyres.
As to the chrome, it needs something to reflect or will render black. Not familiar with the "Ruins" HDRI. Do you have the Yosemite set? There are also several free ones available which provide a background scene.
...restore the shader for the tyres, then when you click on the Iray shiny rubber shader, hold down the CTRL key. this will open a small dialogue that will give you the choice of replacing the current shader or ignoring it. clicking "ignore" should preserve the original shader, but give you all the Iray channels. ANdeasier option would just be to apply the baseIRyshader to the tyres.
As to the chrome, it needs something to reflect or will render black. Not familiar with the "Ruins" HDRI. Do you have the Yosemite set? There are also several free ones available which provide a background scene.
Hi Kyoto Kid, how do I restore the original shader to the tires without messing up all the other ones? I actually did do the ctrl thingy when I applied the shiny rubber to the tires but I want to try again just in case I didn't ( I held control when I added all the iray shaders, altho I think I read you don't have to anymore in the latest release of the beta). The ruins hdri is the new default one that comes with the beta. I am posting a new one with the Yosemite 12 hdri now that I figured out how to get it to show, now how can I see it in the render window so I can rotate and see what its doin, oh and even with that hdri the chrome is still black
...give me a few minutes to fire up the workstation and try a few things and I'll be back.
To see the HDRI in the viewport you need to switch the view settings from Textrure Shaded d to Nvidia Iray (click on the small globe in the upper right corner of the viewport to open the menu). Warning it will take a bit of time to refresh whenever you do something like move the camera or add/move an item.
I would make a copy of the car, apply default shader, change the tire, and then copy the surface, paste it to your car, delete extra car.
Stonemason your cars look amazing, can you tell me how you get the chrome to look chrome and the tires to look like rubber? If you see my renders I posted I am having a bit of an issue with both, thanks
Select the car. On the surfaces tab select the tires. Ctrl-Click the original mat application file. Choose apply to selected surfaces.
@Kharma: I think the DS native metal shader has a black base color. Try the metal nickel Iray shader without control-click on the chrome parts of the car.
Yes understood the fundamentals but without plugging it in and running actual render tests there was no easy way to determine where the break point was. Basically, was trying to point out for anyone interested two things, the xxxx series of NVIDIA won't do GPU rendering, and that the x40 (or below) is basically useless for most people for rendering vs CPU, unless just trying to offload off of the CPU rather then get any increased speed.
...the speed is governed by how many CUDA cores the unit has. the 740 has only 384 not much more than my old 460 with 336. Most of the units in the current 900 series have well above 1,000 with the 4GB 970 having 1,660 and 4GB 980 having 2048.
While there has been a delay both the 970 and 980 are to have the memory upgraded to 8 GB. Prices will probably be comparable to the current units as the Titan -X is priced about the same as the Titan Black (now "out of stock" at Newegg)
This is why I didn't consider the 740 even though it had 4GB memory.. Good you got your money back.
Kyoto,
Have you any idea when the 8GB 970 is going to hit the streets? I'm about to commission a friend to build me a render monster, with a 4GB 970. It would be really annoying if the 8GB version was announced two weeks after I took delivery.
Cheers,
Alex.
There has been an MSI notebook with an 8GB 'video ram' 980 (16+ GB main memory) on the market for over 6 months now*. It appears the video manufacturers are waiting until the Skylake/Windows 10 release due out in fall.
The video card isn't the only thing that will make major changes. If going for a new system you might really want to consider trying to wait until Skylake and Windows 10.
...the speed is governed by how many CUDA cores the unit has. the 740 has only 384 not much more than my old 460 with 336. Most of the units in the current 900 series have well above 1,000 with the 4GB 970 having 1,660 and 4GB 980 having 2048.
While there has been a delay both the 970 and 980 are to have the memory upgraded to 8 GB. Prices will probably be comparable to the current units as the Titan -X is priced about the same as the Titan Black (now "out of stock" at Newegg)
This is why I didn't consider the 740 even though it had 4GB memory.. Good you got your money back.
Kyoto,
Have you any idea when the 8GB 970 is going to hit the streets? I'm about to commission a friend to build me a render monster, with a 4GB 970. It would be really annoying if the 8GB version was announced two weeks after I took delivery.
Cheers,
Alex.
..Nvidia has been somewhat hush hush about it. Form what I gathered last night while checking for updates, maybe mid summer to early fall as the chip release itself was delayed until Q1 this year and it would take several months before the general commercial release of the updated GPUs
Great collaboration going on here on this thread! Really insightful tips on eyes and hair settings for Iray. you don't get that anywhere!
...so what if you have a Haswell LGA 2011 (particularly with a Xeon CPU) based system? Will Skylake be superior to that?
Also still not excited about Win10 after what what I have been reading on the tech sites. Win7 is still good for another 5 years.
...OK here's a test I did.
Only converted the paint, glass, chrome, and tyres.
Used the Cranberry car paint shader for the red, Pearl white for the whiote
Applied the Thin glass shader to the windows with just a hint of bluish green to get the "safety glass" look
Applied the Nickel Metal shader to the chrome (straight, not using the CTRL key) and made a slight adjustment to the glossy colour mking it lighter.
Applied the Shiny Rubber shader to the tyres then changed the glossy colour to black (0 0 0) and adjusted the top coat colour to .50 .50 .50.
That looks really, really good, Kyoto.
The posts to the upper right make me think your Dome scaling might be off, but otherwise, perfection.
This is an involved topic that is to divergent to go into on an Iray thread. I will point out that most people don't have a Xeon processor, so that is a straw man argument. As to the rest, it depends.
for the Fresnel IOR I will get simple, 1.33 water, plastic and woods 1.52 and for very shiny plastic and metallic paints 1.80
it is not possible to create real metals in Iray using IOR values so forget about the science . The difference between the materials are so low that your eye will not even catch it .. the shader is missing extinction coefficient so Fresnel values can't be put exactly as it is in real world
You can use Diffuse under Specular/Glossiness but you will not do that under Metalicity/Roughness as Albedo here would be the choice
so we can have big conversation that go nowhere unless we all are more specific what we doing and present to the forum .
Did this question get lost in the other discussion? Anyone?
As a side note, for my first complete Iray render, at 99% it succeeded in overheating my laptop and shut it down spontaneously. Soooo...if you could add a "Low Heat" option to the menu....that'd be great.
(yes, I forgot to have my cooling fan running)
I looked for a remnant render laying around after reboot, but found nothing.
I finally got the chrome looking ok, but not the tires yet, I replaced original texture as per above instructions, then reapplied the iray shader and then tried both the rubber matte and rubber shiny, neither made a difference I still ended up with this render after 50 minutes, I will retry with your recommends on the tires Kyoto Kid and see how that goes, thank you all for your help, I am happy with my progress with iray so far :)