How to export very large maps
Kit Flemons
🖼️ 4 images Traveler
So, the advice is that one's first map should be small and simple...
I got a bit carried away, and now I have a large, complicated map I want to export.
I've tried exporting it as a PNG, but it's crashed every time about half-way through, except at low resolutions.
What's the best way to export it and keep the quality? (6000pix*6000pix was a bit too small)
I'm looking forward to sharing it here?
Cheers,
Kit
Comments
What size are you trying to export?
The critical number in any export isn't the size you set in the px hieght and width but the work size, which is a pair of numbers at the bottom right of the Options box. If both are significantly over 10,000 px you may have to reduce antialiasing quite a bit to bring them under that number.
When it crashes what do you mean? Does CC3 crash to desktop, or does the process just stop and not finish?
Would you be willing to upload the FCW here so that we can have a go at exporting it?
Hi,
I'm trying 9000x9000 pixels at 300dpi. I've set the antialiasing to 20, so the work size is only just over 10,000.
It's got heaps of badly-managed effects and layers (being my first map, it's not very well organised)!
At some point (half way through or so?) it just closes to desktop, as if nothing had ever happened - it leaves behind the png file, but this is corrupted.
I'll attach the FCW - but it's got the Dundjinni Archives and CSUAC2 packs installed (and also two custom symbols), so I don't know how well that will transfer over.
It takes a number of hours to export (on my computer) though, so you've been warned :D
A number of hours?
Not really appropriate for this problem and right now, but for other maps to speed up the process type EXPORTSETMPPP and hit enter. Check your Maximum Pixels Per Pass in the command line. If its only 4 million type "40000000" (40 million) and hit enter.
Unfortunately, I don't have CSUAC so I can't do a proper actual test on the map, but maybe someone else can try?
How does it render if you drop the antialiasing to 15%, or whatever number you need to drop it to in order to reduce that work size to fractionally under 10,000px each way?
Other things you can do to help include clearing the cache before you export and exporting straight away before you pan or zoom at all. You get to the cache by clicking the Display Speed button
. Just hit the Clear bitmap cache button. My map is only using 63 MB at the moment, but yours may be a lot closer to the limit.
Another option is to render it as JPG rather than PNG, and/or to render it in quarters using the Rectangular Section exports then stitch it together in GIMP or another bitmap editor. This export in parts idea is easier if you have a small overlap on each quarter of the map.
Hi, thanks for such a comprehensive answer! I can try all those. Stitching it together in a BMP editor should be very easy for me (I do that kind of thing all the time) so I'll give that a shot.
What does the Maximum Pixels Per Pass option do?
And how long is a 'normal-long' time for an export?
(Sorry for all the questions - this is the last hurdle now!)
Thanks so much for all the help throughout this first map!
The Rendering engine can't manage the whole job in one go when the export is large, so it divides the map into passes - horizontal strips starting at the top of the map. The smaller your MPPP is the narrower those bands will be, and the longer it will take to render the whole map. The current default of 4 million pixels was set a while back when machines were smaller, so for most people increasing the size by a factor of 10 is a reasonable thing to do. The fewer passes the rendering engine has to do the faster the job is done.
I'm very used to waiting a minute or two for my 5000 px exports with 33% antialiasing (6666 x 6666 work size), but I have my MPPP set to 20 million instead of 40 million right at the moment, so it takes 2 passes to do that size. There's no way a render should take hours.
Incidentally...
Is it crashing after the passes are done and during the processing of the final image from bmp to png? If it is then the sheer size of the resulting png file may actually be the problem. Try for a JPG instead.
Brill, thanks for the tips!
Hmmm maybe that's a point - when I save again, I notice that the filename has been changed to 'Cthulhu Map.png.bmp' so maybe that's the issue?
I don't know when exactly it's crashing - it takes so long I leave it in the background and go and do something else.
Try this way.
Boot your computer up, save thd map.
Don't do other things.
Does it still crash out ?
I suggest this to give cc3+ full access to the computer's memory and cpu.
The ".png.bmp" filename is part of the process. If you see a file with this ending, it basically just means the export crashed halfway through.
Basically, what happens is that CC3+ needs to render the entire map before it can be converted to png, it cannot simply be exported straight to png or jpg, and the native format of windows is BMP. So what it does is that it always exports the file to .bmp first (this is the map.png.bmp file), and then at the end converts it to png (or jpeg) which results in a new file, map.png, and then the original bitmap file (map.png.bmp) is deleted. But if this file is still around, it usually means CC3+ crashed during the export so it never got to the conversion and deletion steps.
Do the crash only happens when you go up to 9000x9000? I see you mention 6000x6000 being to small, so I assume that one actually exported?
Hey everybody,
Thanks for all of the suggestions.
I upped the MPPP to 4million and reduced the map size very slightly (it's still 9,000 x 7,128) pixels.
I'm going to try it again at a huuuuge size with the increased MPPP overnight just to see what happens, and if it fails again I'll do it in four parts.
@JimP Before I left it running last night I closed all other applications, but I don't know how to give it full access to memory and CPU.
It is a monster of a map though... Takes about 20 seconds every time I turn the effects on, or every time I pan with effects on.
I brought this on myself!
Of course, now it's so big I can't easily share it.
There's a Google Drive link here, and I'll try to make a low-res version again so I can show you. (Ironic!)
There are a still a couple of strange artefacts I need to clear up, but it's looking pretty much correct. (Though I forgot to turn the light symbols off... oops!)
https://drive.google.com/file/d/15dFwNC6--aasPawH72P9xHy7vg735UP_/view?usp=share_link
Thanks so so much for walking me through this!
Here's the nice, small jpg!
Just thought I'd drop my $0.02...
I've been toying around with large exports (100,800px * 114,800px - the final PNG had a size of 12.7GB), most of the stuff I've learned, I've commented on this thread (and then this wonderful community shared their own insights)...
TL;DR:
Wow! That map is something else!
Thanks!
It's still a WIP... and probably will be for a long time. It takes forever to fill in details in such a large map. ;)
I was having a different problem with the export this thread help solve somewhat. My problem was the final image being distorted so that the bottom of the map was clipped. That map the grid not line up when the map was used in a virtual table top. I've been using a grid only map (420' x 480' -> 5880px x 6720px) to troubleshoot this issue.
By using EXPORTSETMPPP to set it to 80000000 (80 million), the export of my grid only map exported well enough that the grid is complete.
I still to test this out on full maps to see if I don't run out of memory.
This was a very insightful thread.
Also, nice map roflo1.
Cc3+ is 32-bit software.
If I have a big map, I just work on the map after booting up. I i don't web browse, check email, etc. before I work on a large map.
Ok so thought I would give it a go since I have a pretty powerful computer. Opened fine with all effects turned on. Took about 10 seconds.
What I have done to try and test is set the export to 40million
Export at 9000 x 9000, with default settings and crashed at the very end. Unfortunately do not know where it logs the export to, so not sure at what point it really crashed, I suspect when it was doing the change from BMP to PNG (or when it was trying to launch the image view).
Exported again at 6000 x 6000, AA at None, Launch image view unchecked. Ran fine.
Exported again at 9000 x 9000 with AA at None, Launch image view turned off. Crashed.
It did spend the most time on the CaveLit sheet so maybe there could be something there as well. The others it ran through pretty quickly).
Exported again at 9000 x 9000 with AA at None, Launch image view turned off. CaveLit Effects turned off. Ran fine. Took about 5 minutes in 2 passes.
CaveLitFinalise is another one it spends a lot of time on. Floors Textures is another. Maybe try turning the effects off on your cavelit sheet, and see how it goes? May be able to turn them on one by one until you isolate the culprit. I did not see an effect on the map after turning them off to be honest, so maybe they are not really necessary?
This is what it exported at 9000 x 9000 (although ended up resizing it to 9000 x 7218 keeping the aspect ratiio) - file size is about 50MB so unable to paste it here:
Probably not much help, but I like to make large maps as well. I find sometimes the software fails during printing to CutePDF, but after a while, CutePDF opens and displays the map.
I usually have a lot of applications up while working on a map. When I see a slow down I start closing ones that are not critical and if the problem continues I shut everything down, power down and boot up, then just run CC3+ as Jim states. Sometimes it works, sometimes it doesn't. My computer is pretty old now, so maybe I need a new one.
Hey, thanks for all the help everybody.
In the end I exported it in ~7000 pixel squares, then patched it together in an image editor.
Here's the compressed version.
Cheers!