Iray Render artifacts?
ShazGT
Posts: 15
Been a while since I last posted a question here (Daz Forums), but just yesterday, I finally got around playing a bit with Daz Studio and the Iray render engine. Since October last year I have had my new gaming/general use system. Intel i5 4690K, 8GB RAM (looking to bump that to 16 or 24 soon), and Geforce GTX 980 Ti 6GB, over the months I've been messing with, learning some more, and using for my own personal stuff, Carrara, Vue PLE, Photoshop CS2, and numerous other programs, even Blender and Lightwave 9.0, learning a few things here and there.
Running Windows 8.1 Pro, 64-bit obviously, Carrara is 8.1 Pro 64 too.
But I ran across a Youtube video on Iray in Daz Studio, and finally gave it a try, years ago in C6 or maybe it was 7 Pro, but I had some how in the shader settings, using one of the assets I bought on Daz,
http://www.daz3d.com/f550-italian-sportscar-3ds-version
I somehow created an Iridescent like paint job that seemed to sort of color shift as the car was rotated and such, of course Carrara Crashed, I forgot to save the file, and lost it, never was able to replicate it. When I saw the YT Video and the metallic pearlescent like paint effects demonstrated, I was like WHHOOOOOAAAAA!!!! That's what I'm looking for. Of course Importing models and such from Carrara with various Shaders doesn't import properly or at all into Daz Studio, and vice versa, at least I've never been able to get it to work, some of the DP Veloute shaders I've used in C8, won't render or show right if at all in Daz Studio. I've also played with LuxRenderer in Carrara as well, and it seems to be very specific and limited on what you can actually render with it, let alone pretty confusing for an amateur or newbie when it comes to the render settings on the render tab, the few select situations where it has worked, I was impressed, most of my renders I do, a lot of sci fi ship scenes and such, it just doesn't work for it, but I see this Iray stuff, and has me thinking if I can export a lot of my mesh library to work in Daz, I can utilize Iray for some really nice visuals with some scenes.
Anyways, I couldn't get the model to load in Daz, so I loaded it in Carrara, selected all of it, and exported in Daz Collada DAE format, was able to load in Daz fine now...
I started editing surfaces, and surface settings, not everything but just enough to get a feel for it, and try out the Iray render.
Set my various Render settings for it, and proceeded to render the image.
How ever, one thing that persists every time I render, is it seems some pixels don't render and are left white, or even actually appear when rendering (they could be colored and rendered, then on the next pass while rendering, they suddenly appear), end up showing as white specs, like some sort of artifacting. And wondering how to correct that?
Example here: https://flic.kr/p/G2gBba
(I just saw the upload file option below, and gave it a try, as I know many forums have an upload file size limit, with the image being just over 1.5MB, I wasn't sure if it would work, apparently it does, and can click on that instead of the flickr image link above, but when zoomed it, you can see what looks like specs all over the glass windshield on the car, and the edge of the door is clearly white pixels, like they were deleted though some gray colors looks like it attempted some shading on it, so could be some sort of reflection artifacting or something?)
Its hard to see on the reduced size image in the browser, but if looked at closely in rear seats behind passenger side seat, you can see it, and there's an edge on the door too that shows up very clearly, shouldn't be any if at all much reflection there on that part of the doors edge, and seems like some sort of artifacting, in the full size 1920x1080 image you can see the white spots behind the drivers seat area as well.
I used an HDR image for the background/environment with Ground and Dome visibile.
Same HDR image I used in this Carrara Render a month or two ago: https://flic.kr/p/E3ymQY
I can't remember all my render settings right now, would have to load up Daz and look at them again, but I was unsure on the settings for texture compression, I think by default they were 512 and 1024 respectively, so since I had the VRAM to handle it, I figured why not set it for 2 and 4GB respectively, as I had the same issues at default settings, and I read somewhere that setting it higher could help with some artifact issues with renders some times, so I gave that a try, still no change.
Though its soley CPU rendering (final renders) in Bryce, and Carrara, and to a limited extent GPU but mainly CPU in Vue 2015 PLE (xStream installation of it), I'm wondering if this is some sort of GPU artifacting issues?
Or some setting I overlooked somewhere?
Any thoughts, suggestions or advice? On a quick search, I couldn't find anything on forums, I may have overlooked a thread, if so, I apologize.
(for reference, the GPU isn't overheating or anything either, it was hitting about 58C max when I was rotating the camera while in interactive view mode with Iray enabled in the main view, CPU cores were running in mid 40's, in case anyone was wondering)
On a slightly off topic question, as its still related to Iray in Daz Studio, when it comes to rendering, I know it can use Multiple compatible GPU's, but am wondering if for animations, can it use multiple GPU's like render nodes, or a batch queue? Reason I'm wondering is, in the near future I'm looking at building a cheap, but for me cost effective, rendering machine for personal use, and if and when I can go to school for this stuff, in the next 6-12 months, now that I've been getting a bit more proficient in multiple programs/platforms, playing with different stuff.
But am looking at a Dual Xeon Quad or Hex Core, 16-24 thread workstation build (would also serve as a part time game server for when I'm not rendering), as you can pick up older socket 1366 quad and hex core CPU's for pretty cheap on the used and reconditioned markets from server pulls and the like, but if I can get a board that supports 2 or more dual width GPU's, I was wondering if you can send jobs off to multiple GPU's for rendering animations, like you can for batch queue and render nodes in Carrara with CPU renders?
I have no plans on dropping another $550-600 on a 2nd GTX 980 Ti any time soon (maybe later in the year, if I move to a 4K monitor, or even VR, but I doubt it, I might even consider a lesser lower spec 2nd GPU in my main system, alongside the 980 Ti, so I can just offload renders to it, and then use the main one and CPU for gaming or something while waiting), but if I can get a couple nice cheaper 4GB Nvidia's GTX 760's or GTX 960's, or if I can find a couple of the EVGA 6GB GTX 780's, I might go that route.
Figured if I can offload an animation to a single rig with CPU and GPU rendering, if it will render with both, or just the GPU if that's the case, since Iray is GPU, not sure if its also CPU rendering? Rather than a couple or more separate systems, load down a single one with GPU's maybe? Currently my older gaming PC, an i7 940 based system with 6GB RAM, I can technically add in 3 dual width cards, or go with 2 dual width and 2 single width ones (if I wanted to convert two cards to liquid cooling kits, but that's a lot more money than its worth), it would suffice for the plans I have, but for CPU render software, I want the Dual CPU set up with more threads/cores than I have now, instead of 2 or more systems independent of each other.
As it was, this simple 720p 10 second basic animation using a spin modifier in C8 too well over an hour up to an hour and half to render, in sequenced PNG files, then merged using Virtual Dub, and then using another program to reduce video file size, and then Vdub a 2nd time to reduce further yet (Slow DSL connection currently, upload speed is a max of 800kb if we're lucky, so the smaller the better video uploads). I believe I had most of the render settings jacked up on it too, so that was part of the length, but I tested even with some things turned down, and it didn't make a HUGE amount of difference, so I went back to everything nearly maxed, and let it run.
And that's just for Carrara, with CPU rendering (Could of used render nodes, but I'm one of those who have troubles getting the dang nodes to show up on network, its all installed properly, but no matter what, Carrara can never see the nodes), on a single Quad core, running at 3.5GHz (4 cores 4 threads). Not sure how long something like that would take in Daz Studio, on a single CPU, but if multiple GPU's can speed that up, it would be quite nice.
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Comments
I'm not going to comment about your rig questions or any of the other stuff, but regarding artifacts... Did you let the render go to completion, and did it actually finish? The default is 7200 seconds and something like 5000 iteration passes. Some items need more iterations and more time. I've had renders stop at 30% of completion because they didn't do enough iteration passes. You can try babysitting the render, i.e. watching the entire progress and see if it is actually getting to 95% completion or whatever you have set. Or you can just max out the iterations and see if that fixes it.
What you are seeing are called 'fireflies', and they are a product of the progressive nature of iray rendering. It's an indication of one or more of several things.
1) Insufficient iray iterations. If you leave the render settings for the completion of the render (max iterations, max time, and convergence) at their defaults, the render may 'complete' without reaching the needed convergence to remove all 'imprecise' pixels. Change those settings to allow the render to progress further (usually upping the values considerably, or setting the ones that allow it to 0). Do NOT set convergence to 100%. 99.9% is fine, but Iray can get wonky about reaching 100% convergence.
2) Insufficient light for the camera settings. Use a camera (not just the perspective view) and actually set the tone-mapping parameters correctly for the environment. Some knowlege of real-world camera settings is helpful here. If you do this and the scene becomes too dark, increase the lighting (if just using IBL, increase the intensity setting of the HDRI) values. If the scene is too bright, reduce them. Incorrect lighting for the camera settings is 90% of the problems with grainy images (assuming the iterations/convergence isn't the issue.)
3) Awkward camera positioning. In the scene you show of the car, the areas with the worst fireflies are in dark shadow. While some areas of the car are sufficiently lit (though it looks a bit underlit to me), those areas are getting VERY little lighting. Without very high convergence, you are going to likely have fireflies in the render. If you need that kind of contrast, just render at double or triple the resolution you desire for the completed render, then resize the image in photoshop (or similar) with proper sampling. This will tend to 'average out' the fireflies. Despeckle and low-pass filters can also help (use them before the resizing, though.)
I'm going to agree with Steven-V, and tend to think the render you attached didn't run to nearly enough of a convergence ratio. It also needs more light. So up the settings for the render completion (max time, probably....it's in seconds, and defaults to 2 hours) so the render will get closer to the convergence ratio you have (default is at 95% I think). And also increase the intensity of your IBL.
(and the IBL you are using, based on the render, is probably NOT a real HDRI. HDRI images are different from normal JPGs and PNGs. They have multiple internal layers of differing light intensity levels, and provide many more bits of light information. Use a real HDRI image in your IBL settings.)
The 'Iray server' adds the network rendering capabilities you're looking for.
It has both Batch (queueing) and Interactive modes.
The current DS does not support the Batch option.
Deleted what I originally had posted, I Thought it hadn't posted, but seems to be some sort of delay on forums, after I posted my 2nd attempt reply, in different browser, I refreshed the tab, and it was showing the original reply....
Ugh.... I posted comment and nothing showed up, don't know if its some damn issue with Firefox or what, so trying to repost via Maxthon browser, and see if it does better...
I can't remember all of what I typed but will try here.
First, Thanks for the replies and advice.
2nd, It seems I indeed was not allowing the Renders to fully complete, did not know it would take 5-15 minutes for a still image render like this, using the GPU. When I was doing my renders I was actually cancelling it, but I assumed it was finished as after 5+ minutes I saw few if any changes in the image, and just seemed to sit there, figured it was some sort of bug in Daz or the renderer. Also Alt tabbing between the render window and Daz windows, I never saw a progress box/window, but the PC was bogged down big time, I couldn't even effectively type some text in a document, checked task manager, and sure enough CPU usage was around 95-97%, ironically only 1-2GB of RAM was being used by DS. Possibly some bug or glitch with DS/Windows with so much CPU usage, box may have not shown up, or simply delayed in showing while alt tabbing. When I tried another render the day later, I did see the progress box finally, up to that point it was driving me nuts because there used to be one with the stock DS Renderers, and nothing for Iray, plus there's always been some Progress indicator in every other program I've used, Carrara, Bryce, Vue, Lightwave, Blender, and others. Anyways, now I know there is one, and can monitor it in future.
The day after I created this thread, I tried a 2nd attempt and let it fully render, took something like 12 to 15 minutes for it to complete 100%, a couple other attempts, it got stuck around 65% and wouldn't budge after about 20-30 minutes, I looked at my settings and had a few things stupidly selected, Caustics, Architectual, and what not, no need for those in this, at least not Caustics, but I turned off a few other settings, and tried again, and this time it seemed to work much better.
As you can see in the first attached image, its virtually devoid of those firefly effects from the first image/render above, if you look closely you can still see some speckle like effects in the rear window, and maybe just my monitor, but I barely see some in the illuminated/reflective part of the paint just below the passenger side rear quarter panel window, Though, like suggested if rendered in a higher resolution and then downscaled to something smaller... 1440p to 1080p, or in this case 1080 to 720, to the average viewer its not noticeable.
Might take a bit longer to render, but its something that can be done to fix it in future, or as said, despeckle or low pass filters, in Photoshop or some other software.
The HDR file used, was downloaded here: http://www.foundation3d.com/index.php?categoryid=38&p13_sectionid=440&p13_fileid=2157
Its a small 240x120 size HDR file, didn't realize it was so small, but I've used in a few other renders in Carrara, there's not a huge difference in using it versus not, but a subtle difference can be seen.
I do like the ground under car effect it has in this scene, even if it may not be a real HDR file, or work as one should.
Seemed to work ok to an extent in the 2nd attached image that I rendered yesterday, further testing meshes, and texture/shaders I've used in Carrara for scenes, exported to Daz and imported.
(in that image, I need to see if I can retain or recreate the slight bump/textured effect I can get in Carrara, as well as the shimmer/reflect effect)
Though I did toy with the bloom lighting settings for the environment/dome etc, to give it a slight dream state effect.
Its not a finished scene, and may try changing some settings, as well as add quite a few other meshes later on, dozen, dozen and half or so, and a sliver of terrain in the bottom left portion of the image.
But for right now in meantime, with the car scene, have to try and figure out how to get a mirror or chrome like effect for the mirrors, gas cap and some other chrome/polished metal surfaces in DS, in Carrara I could easily just load some of the stock Shaders or DP Veloute shaders, and be done with it, but so far haven't figured that out in DS, if any stock shaders like that are available, or how to create them if possible, no spare money right now to buy some shader packs that I have on wishlist. Also want to see if I can get a cloth or leather like surface edited on the seats and leather or bumpy soft plastic for dash. The Tires are going to be the tricky one, figuring out to how to get a rubber tread block look and tire like surface to them?
Its just I've been playing with DS in the last few days, after being away from it for so long (at least a couple/few years since I last really used it), a good friend of mine, wants to make the transition from standard hand drawn/painted arts, etc, to Digital art work, at least in part, since he has limited experience with it, not so much in full 3D stuff, but using 3D, and able to combine 2D sketch and even comic like art, and other 2D types with 3D.
His old MacBook really isn't up to the task of some 3D stuff, more basic things possibly, etc, but the Wacom Cintiq Companion he bought recently from one of his old instructors from college, does have potential, otherwise limited to some sketch and other 2D apps on his iPad 2 tablet. Was trying to find some good cheap programs he could dabble/experiment in, including Bryce, and Daz Studio, so started familiarizing myself a bit with DS again, in case he had some questions. He wants to use Maya, but even the monthly subscription price is a bit hard to swallow. So we were looking into cheaper solutions and other stuff he could maybe afford, Blender, PD Howler, Vue 2015 PLE, and some others too (he introduced me to SculptGL in browsers, and Sculptris, both I used and downloaded meshes I played with in Carrara, one of which I used for my avatar, after rendering 30K hairs on its head, LOL).
In the meantime, trying to get him to buy one of my 2 spare systems, for cheap so I can put towards some parts for my workstation build down the road, So he can use for that stuff other than his Wacom, as well as gaming (really wants to get into some PC gaming too). Ones a Mini ITX Intel Pentium G series 3.2GHz dual core with 4GB RAM, and the other is my first i7 920 system with 6GB, either one a good starter system for rendering and what not, cheaply toss in another 4-8GB on the Pentium system, but both will have at least a Geforce GTX 560 Ti in them for the gaming side of things.
Anyways, I'll probably have more questions for DS, will do some forum searching and if I can't find anything post another thread. Besides the shader/texture setting questions, have a few setting/performance, and user interface customization questions.
Edit: Looking at the image, can see some white specs on underside of wheel well area too, so might have some more tinkering with settings to iron out those too.
I looked up the Iray server....
I'm finding it hard to follow this thread -- your posts include a lot of extraneous info about things not related to your main issue. If I may be so bold, it's better to stick to the salient point, and demonstrate what you're talking about in multiple images, preferably with closeups so it's clear to see the artifacts you're talking about. On several of the images I'm not even sure where to concentrate on.
It seems you feel there are white pixels that don't render out. These are very likely fireflies, which another person mentioned. They are often caused by incompatible shader and light settings. You should also make sure the firefly filter is turned on in the render panel.
From your car renders, it appears you are using some point lights (or an HDRi with a very distinct small light source) that is causing unattractively small pinpoint reflections. Specular highlights are fine, but these are unflattering. Opt instead for lights with larger emitters.
If using HDRis, keep the size to at least 1000px and larger. Small images can cause light artifacts. There is a setting in the Iray render panel to compesate for this, but it's better to use a higher definition image.
Perhaps most important, the shaders you are using for the car look like 3Delight shaders that are being auto-converted at render-time. If this is true, you need to specifically apply Iray shaders to your surfaces. This not only gives you better looking materials, but helps reduce the fireflies you may be seeing. There are several freebie and paid automotive shader packs for Iray that give realistic results for paint, windows, rubber tires, graphite, chrome, and other parts.
Added zoomed in views of the spots I notice the speckled effects, much of it seems to be on the windows, some on the paint job.
No, I'm using Iray for the render, and applied the textures/shaders after switching to it.
The file is 3DS, loaded into Carrara with nothing but standard plain grey texture/surface (and whatever the stock windows/glass parts were set for), exported out of Carrara as a DAE file, and then imported into DS, set for Iray renderer first, and then started adding Shaders and such.
I started with all this when I saw this video on my Youtube new video feed,
And followed the first part of instructions starting with switching to Iray, and creating a sphere, and added some color/shaders and played with some settings, and just from the preview render window, was impressed, and proceeded to take a step further instead of using a primitive, actually load in a model/mesh I could edit, first thing that came to mind was this mesh I had gotten years ago, and toyed with in Carrara.
As to lighting, the only lighting for now is the default scene light you start with, I haven't dived into adding in specific lights and such as I was just testing things out to see how it goes, but the incomplete rendered pixels from the first post were bugging me and just didn't seem right.
I'm still getting speckles and stuff in the scene (especially on the glass surfaces, but a fair amount on the outer car body painted surfaces and other parts too), though, after further examinations of the zoomed in pictures, a lot of surfaces inside the car have a lot of default reflective like surfaces that shouldn't be that reflective/shiny in real life. The seats for example, the dash, etc, even the tires are too shiny. I tried a stock matte surface setting, but the color for solid black is really faded looking almost a dark grey, so I switched back to a plastic for now until I can do something else with it, may have to tweak reflection settings and such way down.
Aside from the stock light, only other source possibly would be the HDR file assuming its even an actual or close to it, HDR file.
The weird thing is, the other picture, the Babylon 5 Shadow vessel render, though the mesh/model is further away from camera view (have saved both renders using a Camera view, not just perspective, but the camera is set for same coordinate/position as perspective), there is no speckles or fireflies at all in the render, at least on the model/textures used (can't tell on the HDR image file used for Dome and Ground), the ship isn't using any textures or shaders from DS, in Carrara it was a LWO or 3DS file, possibly OBJ file, I have several variants of meshes made by others that are similar but slightly different in those formats, but I'm pretty sure this one was a LWO file, as I've loaded it in Lightwave, and it looks much better, not just texture, but polygons and shape.
I exported it just as I did the 3DS file, however the textures were set for converting procedural shaders to textures upon export, and allowed to import fairly intact into DS, I tried another render where I used the same exact texture on it, completely redid the ships surfaces with it, seen here https://flic.kr/p/E3ymQY ; but, I also exported this in the same way as the Shadow Vessel in that attached image up above, it did import the textures to DS, but only some surfaces have them applied, and the ones that do are skewed and stretched/warped looking. That same ship/render, I also tried exporting merely using the texture settings, and no change procedural shaders to textures option, when imported into DS, it was just flat black colored surfaces with no signs of original textures.
With that said, the other ship imported fairly intact as far as textures go, and with no speckling and fireflies on it, using Iray renderer, even if I didn't use Iray textures/shaders, it has me wondering if this is a DS and/or Iray render issue with lighting or textures/settings used?
Thanks for the closeups. They help.
The fireflies are almost guaranteed to be from poorly set shaders. Even if they are Iray shaders, the car looks very dull and fake -- who has white plastic interior?! I think you should spend the time looking for better shaders. As I noted, there are plenty of free/paid shaders that can produce car textures that are 99.99% realistic looking.
For a car, forget importing textures unless you need to carry over a base color with an image on it. You don't need or want a texture file for car paint. Use a car paint shader in the color you want. Same with interior, glass, everything. (One notable exception could be the tires, but here, all you want is the base color texture image, and perhaps bump, added to an Iray rubber shader.)
At least some of the fireflies might be coming from the glass. You should select a glass shader based on the type of geometry for that glass -- glass with no poly depth should use a Thin shader; otherwise you can use a volumetric shader where you have more control over how the light passes through the plane.
Don't rely on things that worked in Carrara or Vue or anything else. iray works completely differently than any of these. Do a search here for some free HDR images that people have demonstrated give good results. Forget the image they display; concentrate on the lighting you get. Consider doing test renders with primitive shapes, using the shaders you intend for your car. Tires should look like tire material; wheels should look like mag aluminum or whatever you intend; car paint should have a deep luster; seats should look like Corinthian leather, or whatever.
For the diffuse color (base) texture, here's an example of where you'd want to keep your maps, because they are integral to the render. All surfaces in this render were converted to Iray, with maps kept as needed. Other parts where there were no maps to carry over (or I didn't want to) were applications of standard Iray Uber shaders, or Tom's carpaint shaders:
http://tom2099.deviantart.com/art/DS-Iray-car-paint-shader-presets-tom2099-521788717
The windows are not tinted; this vintage of VW didn't have tinting, but if I were to redo this render, I might fiddle with the glas a little more to bring it out. The yellow turn lights were also not carefully selected
This was a quick test render I did months ago, and so there are unconverged pixels (salt/pepper sprinkles), but you can also see some fireflies that should be attended to. After getting the shaders to look the way you want, go through the lights and shaders to improve performance and reduce artifacting. The following nVidia PDF has some good tips on the matter:
http://irayrender.com/fileadmin/filemount/editor/PDF/iray_Performance_Tips_100511.pdf
The document doesn't cover all of the causes. For example, you can also get fireflies when there are internal reflections from overlapping geometries, a problem common to the eyes in most Daz characters. It can require a bit of work to get rid of these, or else use of a well-designed shader product for the human body parts. Some of the newer shaders for sale in the Daz store do a better job than the older products, so read the forum threads for user recommendations.
One area that you may want to consider maps...bump/normal maps for the lenses. Often cars do include a bump or normal map for the light lenses and that would be on of the ones to keep.
The surfaces look too shiney. When something is really glossy it can take longer to clear up the fireflies