Blender cycles baking textures for model is VERY slow.

[Exurok [SBG]]

Compared to the viewport render i can thanks to my 1080 have it done pretty fast.
I read that blender cannot use GPU for baking textures, and reading around also seems to confirm this even for 2017 2.78.

Is there a work around?

some textures takes hours..

[Scre]

get more RAM and better CPU :P

[Pte Jack]

Turn off animated baking if your computer is slow.

[Mr Chappy]

Hi,

I don't use Blender for baking, I use Substance Painter to bake the normal maps for the low poly model and then paint. When baking a full set of starter maps at 4k, Normal, World Normal, AO, Curvature, Position, and Thickness, it never takes as long as an hour...

So I'm wondering what you are trying to do exactly as there are different types of baking.
Have you tried using Blender Render for baking rather than Cycles, unless you are baking lighting(which I'm guessing you're not?) then I'd assume the results would be pretty much the same...(can anyone confirm this or not?)

Are you baking maps for use within a game engine?
How complicated are the materials that you are baking into textures, assuming this is what you are doing?
What size textures are you trying to bake and how many?
If you are going for 8k textures then this could be a problem, my PC quits out of Substance Painter if I try this for the most simple of tests. Like Scre says RAM can be a big factor as textures eat it up like nothing else....

[Exurok [SBG]]

Im sorry for so little detail.
Yes, im doing lighting bake for my objects so that the final movie will go faster. since textures are pre baked and used as emitters. Only statics tho.

[Mr Chappy]

Originally posted by Exurok:

Im sorry for so little detail.
Yes, im doing lighting bake for my objects so that the final movie will go faster. since textures are pre baked and used as emitters. Only statics tho.

Then the time does not surprise me, baking lighting for full scenes can take an age, a complicated scene an eternity... I had to leave my old machine on for well over a day in a frozen state when baking light in a scene in Unity....

[Exurok [SBG]]

Hmm. ok, but this is an intel i7 4790k OC to 4.5ghz. The textures are only 2-4k some 8k still this is normal? 16gb 2400mhz ram too. all on a SSD.

[Mr Chappy]

Originally posted by Exurok:

Hmm. ok, but this is an intel i7 4790k OC to 4.5ghz. The textures are only 2-4k some 8k still this is normal? 16gb 2400mhz ram too. all on a SSD.

It sounds right to me, your system is a bit better than mine, but not massively and some 3D stuff makes my rig chug and die sometimes... Some things just take time. It is doing more work here than it would during a std render.
In a render the rays are traced backwards starting from the camera, so only relevant data is processed.
In baking your whole scene all the light information must be baked and processed and at a resolution that matches each texture. A render may be around 2k, some of your textures are 8k which is 16 times bigger than at 2k. and it is doing this for every texture!
So my best guess is this is normal, though I have only done light baking in game engines and not in Blender...
In a game engine the light data is stored separately from the textures as a lightmap, they can have different resolutions from the textures that they correspond to, which in turn can save time but does use more RAM as it is yet another set of textures. I don't know if this method is an option in Blender or not, or if this would be of any real use if it were available as the quality would drop if you used smaller lightmap sizes....

[Mr Chappy]

You might want to have a think about dropping your textures down from 8k to 4k regardless and so on... 16GB of RAM is the same as I have and I've been struggling to get by on it more and more recently.

For a full scene with multiple layered 4k textures(I tend to use four maps per material with a pbr node setup) mixed with 2k, many 1k and many less than 1k textures I find I'm going over my RAM limit a lot and having to drop texture sizes.
Blender does not quit out when this happens. It slows to a crawl and I think it attempts to swap data in and out of RAM or possibly use the HDD...?

Have you checked your RAM usage when baking? It is normally a lot higher than the RAM usage displayed along the top of the window before rendering and I'd imagine the same is true for baking light.
You could also have task manager open as another way to view what is happening.

[Exurok [SBG]]

Ohman just did. at a 4k texture i use 90-98% of my ram. Hmm.. do you think doubling my ram has any advantage? or should i triple it?

[Mr Chappy]

Originally posted by Exurok:

Ohman just did. at a 4k texture i use 90-98% of my ram. Hmm.. do you think doubling my ram has any advantage? or should i triple it?

First have a good look and see how much difference there really is quality wise between a 4k texture and a 2k texture. With many objects you will find pretty much no difference at all, sometimes you can go even lower, maybe much lower.
Do this for all of your textures in your scene and see what saving you can make with little actual loss of quality. I tend to have no more than around two or three 4k materials in a scene and I have them where they really count.

Have a look to see if you can use lightmaps in Blender, if so you can use lower res maps for the baked lighting, then you can combine these in any paint package by enlarging them to match the textures sizes and using multiply, this avoids having extra RAM used by them.
If you can do this and do do it then keep a back up of the un-combined textures and lightmaps as this is not reversible.

Have you tried baking in Blender Render to see if this reduces the system strain at all, it might not but it is worth trying all the same.
If it does then the results might not be as perfect but may be pretty good, you would still be able to do your actual render using cycles with the baked textures. The biggest headache would be making the lights(strength etc) match up between the two, there might be info on this somewhere if you do a Google?

I don't' know if you can do this type of thing is sections and combine the outcomes for a close approximation but that might be another option.

Lastly yes you can get more RAM, but that costs... I do not know it all by a very very long stretch so getting more info on what can be done from other sources is a very good idea!
The recommended specs for a pro build have 16GB of RAM listed on Blender.org.... I could have sworn this used to be 64GB for the pro build a few years back so maybe there are optimisation tools or procedures that have been introduced that I don't know about, or maybe I simply remember wrong.
Or maybe they just put a lower spec on the page now or the spec list I read could have been on Blender Nation or somewhere else? 8k textures were not about when I thought I had seen it listed as 64GB and 8k are sixteen times bigger than 2k so I could well believe that having 128GB or more would be desirable now....???
Have a google and a read to see what others say on this before you invest in more, I might have a look later too! If you find any good info on this then post a link for me and others to have a read if you can, thanks!

[Mr Chappy]

One last thing, what is your RAM usage in Blender(displayed along the main window's top bar) before you apply any textures in your scene?
To easily find out make a copy of your file. Remove all materials in the temp copy(see link below) then see what is says.

http://blender.stackexchange.com/questions/7160/can-i-delete-all-materials-of-all-objects-in-a-scene-quickly

RAM is again the limit for how complex a scene can be, there are definitely some clever tricks that work in some situations to get around this but when they don't it can result in rendering the scene in parts and combining these in composition later.

If your scene is easting up your RAM before you even get onto texturing, baking etc then that could be the route cause of your issue...?

Can you post a pic or two of your scene?

[Exurok [SBG]]

Thanks for these helpful and awesome tips Mr Chappy! :)
The scene is not that important, the answer is within your replies. i'll go right ahead and fix up.