Iray Preview Slow as Molasses
vonHobo
Posts: 1,682
Is there anything faster than the Iray Viewport Drawstyle preview that does not slow down the PC and still provide visible HDRI and shadows?
I've tried every other drawstyle for the Viewport, and none of them seem to provide real light shadows.
I don't think they display HDRI either, unless you use Iray as the preview.
The problem is that Iray is sooooooooooo slow!
It adds hours to my work going back and forth from Iray to other previews, just to get a little work done.
It just amazes me that DAZ Studio would not even have a simplified Iray preview.... anything at all.
I can't afford a hydrogen-cooled supercomputer right now. Is that what it takes to get a good "working" setup?
As you can probably guess, I'm seeing red right now!!! And steam is coming out of my ears!!!
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Steam can be used to power a powerplant for the liquid hydrogen cooled supercomputer
Why use an archaic technology to power a state-of-the-art computer? Nuclear fusion would be a better choice.
Realistically, you're probably better off just working with a Texture Shaded viewport while making occasional short test renders in Iray. Most of the things you need to check can be seen in the first 50 Iray samples, maybe fewer than 50. That might seem counterintuitive or a technological step backward, but using Iray for previews will slow the work process with every camera movement or any other minor change. Once you get multiple characters and complex environments loaded, Iray previews can become quite sluggish and slow even on high spec machines.
I was thinking of using a very small size viewport and then only sizing up on the final render. But I don't know if that will make much difference.
Will smaller viewports display Iray previews more quickly? Or should I stick to your advice and just use a texture shaded viewport?
It's really frustrating, because even texture shaded is not a good representation of light and shadows, and no HDRI preview at all.
Have you got Display Optimization set to "best"? In older versions of DS it was set to none by default but I believe the newer versions have "best" as default.
Thanks. I checked this setting and mine is already set to "Best".
When something is set at "Best", the computer is working harder and taking more time to achieve the required level of quality.
Better and Best options take advantage of newer GPUs and will reduce the load on the CPU and improve speed, but at the risk it will not be supported on older GPUs. If VRAM is low, performance will be terrible because the driver will spend a lot of time swapping between system memory and VRAM. We don't know the OPs specs but even when I had a GTX 960 using the Best option made preview responsiveness far better than the None option. If the OP is experiencing "hours" to go back and forth from Iray to other previews, he/she either has a very low-end GPU and/or is working with a very demanding scene.
Reducing the CPU Load Limit when setting up a scene won't improve the speed of the iray viewport but it will free up the cpu for performing other tasks which can be a big part of the frustration!
it's located under the advanced tab in your render settings...have your task manager open and lower the limit to see what effect it has on the CPU%.
Personally i'd like to know the pros and cons of playing with this function as Daz allocates all of the CPU as default but obviously its the GPU that takes up the heavy lifting during rendering?
(it's something i've never even noticed on my more powerful desktop but defenitely comes into play on my laptop!)
Wish they had a simple matcap/workbench style renderer using the Filament renderer.
Filament is faster (at least on my PC) than most of the other viewport drawstyles and has shadows etc. I pretty much use Filament now instead of texture shaded.
I tried Filament when it was first introduced on DAZ Studio, but it crashed my PC.
I have an Alienware Aurora R7 desktop purchased in 2018 so it's not state of the art, but it's not bad.
I may try Filament again if it is a faster preview than Iray.
Just tried Filament again. It works great.
I'll use it in place of texture shaded... it even shows HDRI backgrounds.
It does not show shadows or emissive lights but it's better than using the super slow Iray preview.
Thank you for the suggestion!
However, when I add Filament drawstyle button to the toolbar it does not change the view, it appears unclickable (greyed out) and I have to use the Filament preview from the Drawstyles dropdown instead. All the other viewport drawstyle buttons work from the toolbar. Strange!
I too notice a major difference between filament and iRay. What I notice is that the mesh smoothing is calculating each item in the scene before allowing any movement in iRay. Each tiny movement for a single joint starts an update of EVERY smoothed object in iRay. Posing and positioning in iRay is a nightmare if smoothing is turned on. The characters jerk wildly and intermittently while posing, waiting for long and discontinuous smoothing updates.
Filament does not update the mesh smoothing while posing. Is there some workaround for iRay?
You could also try creating a camera, and setting its Headlamp Mode to off. Depending on the specific scene, perspective view is ridiculously slow in iray whereas a camera without built-in light is super quick. Obviously your scene needs to be lit somehow. It just sucks in terms of undo/redos because moving the camera around is an undoable action so you can reach the limit quick.
realistically, you will enjoy eating molasses better. For a better preview than default use the filament render engine
I've got a computer that's cooled by water, which has hydrogen in it. It's fairly super. Iray preview still has limited usefullness.
I found that the beta was better for Iray preview, don't know if that's still the case as I only have the beta installed now.
Cameras with lights attached are still a no, I can navigate around a scene fairly smoothly but moving stuff around or posing is awful.
I work in filament and switch into iray preview just to tweak lights or place decals or section planes. Iray preview also uses more power, which means more heat and noise.
I use and rely on the iray preview all the time, it might be kind of slow ( I have a 2080ti), but I would be lost without it.
IBL Master
https://www.daz3d.com/ibl-master-for-daz-studio ;
No need to create a camera for that, just turn the ehadlamp off in Render Settings>General.
Render Throttle works for me to speed things up immensely with Iray previews. It's worth a try.
https://www.daz3d.com/render-throttle-for-iray
Without Render Throttle, my PC fans just keep going with Iray Preview, and the PC slows to a crawl. It's pretty much unusable!
With Render Throttle, the image appears in the viewport fairly quick depending on the complexity of the scene. But then once it appears, the fans on the PC stop running and the PC is no longer in overdrive. It allows me to get stuff done. I don't know what kind of voodoo magic this Render Throttle product uses, but it works!
...I've been noticing from time to time that in Iray view the image sometimes dosen't resolge and remains pixelated.. When thiis happens I have to save the scene, close, restart the programme, and reload tehscene which and be a bit timeconsuming and frustrating.