Too Much Time To Render iRay ... Why ?
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Hello... i have read all people 2 min... 5 10.. 15 min to render an image ! why me take 40 min some time 1h and 30 min for 1 image ? i have set to 1080 with 2 character in an station train ! i have i7 8700k , GTX 1080 ti Strix 11gb , 32gb ram ! ..... where i wrong or it's that the time to render 1 image !?
Please help because i have so many images to render and im lazy to leave the pc every night to work ! Thanks
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It depends on your image and your render settings. You haven't given anyone enough information to help. A 40 minute or 90 minute render may not be unreasonable for a 1080, depending on settings and scene content.
It depends on many things why some renders take longer than others. Light is one big thing and also reflective surfaces, glass... and, some Hair takes ages to render too.You really should give some more information.
With your system and 2 fully clothed characaters in a complex tran environment, 40 minutes isn't bad. Lots of other factors as noted my also be in play. How big is the image you are rendering? what kind of lighting? subdivion or not?,etc.
The title "Too Much Time To Render iRay ... Why ?"
In comparrison to what?
Comparing your time with random numbers from other folks isn't actually a comparrison.
Compare like for like; find the thread where folks upload the render times based on the same scene; compare yours with others of a similar setup (mainly graphics card like-for-like).
If yours is still taking longer, then ask your question.
...dark and interior scenes also take more time than outdoor daytime ones.
Crikey If I could get a "realistic" quality Iray scene down to 90 min I'd be happy as my scenes usually end up on the CPU (and even swap mode). For me it's start the render before going to bed and hope it is finished when I wake up the next morning.
I had one night scene using Urban Future 5 and just one character (Mila) a single ghost light, with just about everything outside of the camera's field of view turned off (including emissive lights) as well as converted the street lights that affected the scene to photometric spots, and the next morning (about 9 hours) it was still rendering at 78% complete and very grainy.
I had a render going for 24 hours, I'll take 40 minutes any day! Lmao
...one member here who rendered Jack Tomalin's Library with the Iray materials add on set (CPU Mode) had it take nearly two days to complete. Iray is not very friendly with older hardware.
Yes, what Kyoto said about light levels is what I had trouble with and sometimes still do when I first started rendering in Daz. I'm sure there is a ridiculously in-depth Siggraph level explanation for how dim light diffuses light rays and how many times it has to bounce(which the cpu/gpu will use to tell it what kind of pixel to put where) but I simplify it for myself. The darker it is the harder I have to work to make out detail in the corner of a room for example, and the same for the PC which is using algorithms instead. Except if you have some highly detailed item in that dark space now it has to try to compute all that height information, subsurface scattering, etc, all with minimal "feedback" or light.
Its also hard to "see" if you're staring head on at a car's hi-beams too, so too much light can cause a long render as well (or it has in my cases.)
I hope that makes a shred of sense. There is a lot of tutorials on speeding up renders floating out there, which go into what to do more so than the why. Good luck!
...the super long render times on the CPU, particularly for interior and evening scenes, is part of what caused me to move back to 3DL. I tend to do fairly big scenes at high quality and large size resolution with lots of characters and/or stuff in them, so no way can the GPU card I have hold them in memory for very long.
Yes, I've yet to bother with 3dl though I really should not limit myself to IRAY. It's what I started with so I never learned what came before. I've been trying to handle big scenes with render layers and compositing, but that can be a nightmare at least for me. I took a crack at a scene scene I've been trying to render well for months before I went to work and here I am getting home with 10 hours at 29 percent. Low light, high res, and a ton of textures. Octane couldnt handle the texture memory.
My advice:
Always use more light. If you want a 'dark' scene, just make sure most of the light is very even/diffuse, and then adjust it in post.
Use Iray Canvas. (Go into Render Settings, advanced, click Canvasses, click the + to add a beauty canvas). This will output a png render as well as a 32 bit EXR image in a folder with your save file name. (So if you call it Boise, you'll end up with Boise.png and then Boise/Boise_Beauty.EXR or something)
Photoshop and I think GIMP can convert the 32 bit exr into 16 bit, which you can then more easily adjust to your liking. 16 bits gives you more 'room' to brighten or darken without getting an obviously pixelated look.
Advice 2:
If you aren't super insistent on highly photorealistic results, go into Render Settings/Optimization and set Max Path Length to 3. If eyelids or other transparencies look noticiably weird, bump it up. This can _hugely_ speed up render times.
Advice 3:
Avoid all transparency/SSS/volume effects. Use old fashioned cutout opacity wherever possible. Human figures will probably look just fine at medium to long range doing this, though closeups won't work as well.
But if you can combine 2&3, you can double or possibly triple your rendering speed.
Thanks Oso that has cleared up a few things for me, hopefully the OP as well.
Often when I see this claim pop up I kick it around a bit for personal curiosity. I have always found that unless you reduce the max path length enough to cause a noticeable downgrade in the image, the reduction in render time is minimal.
For example, this is a dispersive glass sphere in a diffuse reflection only gray box, with three tiny white emissive spheres lined up horizontally, caustics on, rendered to 99% convergence.
Path Length 3 (just an example of "obviously need to move a step up")
Path Length 4, 188 s
Path Length -1 (infinite), 202 s
So here the additional time from making the path length infinite instead of absolutely minimal is only seven and a half percent more, and see how we have still lost all those pretty light reflections inside the sphere.
Here is someone testing with diffuse surfaces only on DA, similar results.
http://fav.me/d8nooal
To me this is just not worth potentially having a glaring lighting screwup that you couldn't check for until the render finished. Is there a different sort of scene that gets very high reductions in render times without degrading the image? A bunch of stacked transparencies maybe?
Render in daylight use HDRI for light source. Read up on Iray or pay for tutorials here or online for free. You have good hardware most of these rendersyou are talking about are single characters with HDRI lighting and no background. Dark renders or indoor renders are take more time and are filled with fireflies. Speed tip Render with more light and Render Huge dimensions and use Gimp or Photoshop to downscale your image this works very well.