Long Render Times with GTX1070

josephlemons69_4db0991b45

So I have an image I want to render but I wish I knew how to speed it up, im using a GTX1070 dont know why im having a problem lol, I dont think it should be taking this long, Does rendering at 4K make a difference in render time? I am using the Beta with GTX1070 and my renders seem to take all day?

GaryH

The larger the image (more pixels) the longer it takes to render.  As an experiment, try your rendering at HD resolution - it'll render much faster.

SpottedKitty

There's another more important factor; how big and complicated is your scene? Remember, the whole scene, geometry and textures, must fit into the memory of your graphics card, otherwise the render will fall back to the (much slower) CPU processing.

Thomas Windar

Depends - what is your point of reference?

If you were making 2K renders in 15 minutes and now you are making a 4K one and wondering why its still not as good after 35, then remember that 4k is not 2x 2K but actually 4x 2K. So the render power required is x4 and not x2. 

Aside from that - like others said - are you using your GPU? Did your scene fit into the Card's RAM? 
Maybe some details on what you are trying to render? 

josephlemons69_4db0991b45

Thomas Windar said:

Depends - what is your point of reference?

If you were making 2K renders in 15 minutes and now you are making a 4K one and wondering why its still not as good after 35, then remember that 4k is not 2x 2K but actually 4x 2K. So the render power required is x4 and not x2. 

Aside from that - like others said - are you using your GPU? Did your scene fit into the Card's RAM? 
Maybe some details on what you are trying to render? 

Here is what I was trying to render

mjc1016

I can render about 10x that number of polygons, in about 20 mins on my 1 GB GT430...so what that shows isn't telling us very much  (trick to doing 3.5 million polys...no textures at all).  What size and how many texture/image maps are assigned to those polys and what kind of surfaces those are (higly reflective/refractive ones will take longer) will be more of a determinig factor to how fast it will render than total number of polys. 

On a side note...that 350,000+ poly scene is going to use around the same memory as two 4096 x 4096 image maps...and the typical Daz figure has more than a dozen maps.

josephlemons69_4db0991b45

 

mjc1016 said:

I can render about 10x that number of polygons, in about 20 mins on my 1 GB GT430...so what that shows isn't telling us very much  (trick to doing 3.5 million polys...no textures at all).  What size and how many texture/image maps are assigned to those polys and what kind of surfaces those are (higly reflective/refractive ones will take longer) will be more of a determinig factor to how fast it will render than total number of polys. 

On a side note...that 350,000+ poly scene is going to use around the same memory as two 4096 x 4096 image maps...and the typical Daz figure has more than a dozen maps.

Here is what Iray Memory Assistant says if this helps at all 

 

mjc1016

It shows that even with 3 (at least) subdivided figures in your scene and using compressed textures, the amount of memory used by the image files still outweighs the memory used by the geometry.

It also hints that you are going to have a few highly reflective surfaces...it's a bathroom, right?  That will increase time.

But it does leave out one important fact...lighting.   How well the scene is lit and what type of lights are used has a big impact on the render time.

josephlemons69_4db0991b45

Can you reccommend any light sets from the daz store or will any lights work, right now i am using one of the key lights from Render Studio Iray by Colm Jackson and ome of the architecture lights from one of the architecture lighting products, forget which one, .|can you translate what you said below into something easier to understand lol, what you said makes no sense to me

mjc1016 said:

It shows that even with 3 (at least) subdivided figures in your scene and using compressed textures, the amount of memory used by the image files still outweighs the memory used by the geometry.

It also hints that you are going to have a few highly reflective surfaces...it's a bathroom, right?  That will increase time.

But it does leave out one important fact...lighting.   How well the scene is lit and what type of lights are used has a big impact on the render time.

 

mjc1016

Okay...the textures are using more memory/resources than the models, even with the subdivision levels on at least 3 of them (can't see the rest of the items in the scene, so I can't say what any of them contribute).  So they will be more 'costly' to render...take more time to process.  And the more 'real' a surface is...the more it acts and is following actual physics, the longer it can take (a reflective surface, like tile will 'infinitely' reflect,  or another way there's no limit to what it can reflect...). Iray, by default, is set to try to calculate as many of those reflections as possible...it has no 'cap'.  So highly reflective surfaces take longer to render...especially in less than optimal lighting.

Now back to the lighting...with what you said you are using, there's a good chance that it is less than optimal for the scene.  So, while eventually it will result in a good render (without the default 'stop' conditions, Iray will try to calculate everything...(by default those are 2 hrs, 5000 samples or 95% convergence--converged pixels are those that Iray has determined are no longer changing, with continued calculations), it won't do so very quickly.

josephlemons69_4db0991b45

mjc1016 said:

Okay...the textures are using more memory/resources than the models, even with the subdivision levels on at least 3 of them (can't see the rest of the items in the scene, so I can't say what any of them contribute).  So they will be more 'costly' to render...take more time to process.  And the more 'real' a surface is...the more it acts and is following actual physics, the longer it can take (a reflective surface, like tile will 'infinitely' reflect,  or another way there's no limit to what it can reflect...). Iray, by default, is set to try to calculate as many of those reflections as possible...it has no 'cap'.  So highly reflective surfaces take longer to render...especially in less than optimal lighting.

Now back to the lighting...with what you said you are using, there's a good chance that it is less than optimal for the scene.  So, while eventually it will result in a good render (without the default 'stop' conditions, Iray will try to calculate everything...(by default those are 2 hrs, 5000 samples or 95% convergence--converged pixels are those that Iray has determined are no longer changing, with continued calculations), it won't do so very quickly.

Ive always had trouble lighting indoor enviroments, how would you go about doing it or is there a way that works in most situations, are there certain lights that render faster like mesh lights, is there a way to optimize my scene so it renders faster, is there a way to turn textures off if they arent visible to the camera or make them smaller, does changing the iso speed up the render at all or not

mjc1016

Changing the tone mapping doesn't really speed anything up...it's more for setting the tone/mood of the render.  Think of it as 'over exposure prevention'.

Indoor environments are just more difficult to light and take longer to render...because a single ray will bounce around a long time before Iray figures it's 'lost' enough energy to not count any longer.  Something that can be done is to set a 'cap' on those ray bounces...

Under Optimizations, in Render Settings set the Max Path Length to something between 12 and 24.

nicstt

Sometimes, opening up a room, getting rid of walls (and possilble ceiling) that aren't in view, and have limited effect on reflection can improve times - sometimes not.

Also, I will render figures in a scene, with the props in place, then render the room seperately; that can speed up times (it can also drastically change the look of the characters, so doesn't always work).

Also spot rendering, and then changing the mode to windowed can speed things up; you combine the parts you spot-rendered afterwards (Gimp, Photoshop and others); the majority of many scenes renders much faster than smaller but important aspects; accepting the full render with some grain, allows one to render those sections that need it seperately.

josephlemons69_4db0991b45

nicstt said:

Sometimes, opening up a room, getting rid of walls (and possilble ceiling) that aren't in view, and have limited effect on reflection can improve times - sometimes not.

Also, I will render figures in a scene, with the props in place, then render the room seperately; that can speed up times (it can also drastically change the look of the characters, so doesn't always work).

Also spot rendering, and then changing the mode to windowed can speed things up; you combine the parts you spot-rendered afterwards (Gimp, Photoshop and others); the majority of many scenes renders much faster than smaller but important aspects; accepting the full render with some grain, allows one to render those sections that need it seperately.

 

Ive heard about spot rendering before, how do I actually use it? 

DrunkMonkeyProductions

just my two cents

spot render tool

Alt+Ctrl+C

activates the spot render tool.

It changes the icon to a camera/pointer, then you simply click/hold your mouse button and drag to expand the selection to the size you want.

 

One of the biggest problems with spot rendering is that it only gives you a portion of the scene and doesn't always provide enough information to make a decision about lighting. It also goes away as soon as you click on any point in the viewport. so you can't reference it as you make changes.

Also, depending on screen resolution, it can take as long to render a spot as it can to render a larger version.

Personally i usually prefer a smaller version, 500x500 for instance. This provides enough information to decide where i need to increase/decrease lighting, make changes to positioning etc.

the other advantage is that i can look at the render as i make changes in the scene, then render again.

Of course you can always use the IPR view. It's a RTR, real time renderer, for iray.

It's a resource hog, but can provide faster feed back.

 

Now as far as ighting suggestions.

I don't personally ever recommend any pre done set of lights, the main reason is that the variables of lighting don't lend themselves to presets very often.

Light sets for specific architecture is an exception, but still usually requires some major tweaking.

 

For your bathroom scene, does the room itself have any light fixtures?

if so you may want to convert those over to emissive shaders, just scroll down the surfaces tab till you find 'Emissive', it will be set to black by default.

You'll have to play around to achieve decent results. This will of course depend if the fixtures actually have bulb(s) or not, a lot of older sets lack actual geometry for a light bulb.

Depending on position, and number you could easily light the entire scene with those.

One major thing to check is if your camera's "headlamp" setting is set to Auto/off/on, default is Auto.

If there are no 'lights', spot, point, distant, it will generate a light source, If your render settings are set to dome and scene, the default.

When i'm using mainly emissives, i either turn it to off or add a point light, but place it below the floor so it doesn't provide any light in the scene.

As far as any other suggestions, i'll take the usual route and recommend getting a copy of jeremy Birn's "Digital Light and rendering",  as well as any books on the subject of photography.

 

One more thing to consider regarding your scene and render time, is if you are using only iray shaders or if you're using default 3delight shaders converted automatically to iray.

When the auto conversion takes place, 4.9.2.7 at least, the shaders are usually converted to a more metallic, higher reflection more light bounce calculations, than if they were the equivalent iray shaders.

So you may need to convert those over to the base iray shader then adjust the various settings, of get some of the various shader presets and convert over, reapplying the original texture maps to the appropriate channels.