Rendering problems becoming more serious

A while back, I reported on some rendering issues (here). From that thread, I understood that there are certain limitations in the program when it comes to the maximum image quality that can be rendered. Those limitations are manageable. A bit annoying, because I'd be perfectly happy to sit through a render that took two hours or something if it produced a super high-quality image, but I can't since the program crashes. But alright, I can make do.

But now it's getting worse. Any render requiring 19 passes or more just fails, and ALWAYS on the 14th pass. The program crashes. If the whole render is 18 passes or less, then it works fine. Doesn't matter if effects are on or off.

I'm starting to suspect that as I add more stuff to the map (rivers and text and etc), that's making the problem worse. As it has more stuff to render, the number of passes it can get through before crashing decreases. If this pattern continues, that's going to present a rather serious issue... This map isn't even halfway done in terms of how much junk I'm going to be putting on it. Is this going to just get worse and worse, to the point where I have to cut anti-aliasing and/or resolution way down to low quality just to get the thing to even produce an image file?

Is there any kind of solution to this otherwise excellent program's frankly miserable rendering capability in the works?

Comments

  • What size is the map in pixels ? CC3 doesn't use your video card and only uses 2 gigs of regular ram.
  • Posted By: JimPWhat size is the map in pixels ? CC3 doesn't use your video card and only uses 2 gigs of regular ram.
    Yeah, I remember that from the other thread. I do wonder if there is a way to change that, to allow the program to utilize more resources while rendering. Seems to me that might solve this problem entirely.

    As for my map, I'm exporting at 6000x4000. Which is fairly large, but it's also a huge map - 2100 km east/west by 1300 km north/south. And it's intended to be a map of an entire nation (using the Modern Political annual style), so there's ultimately going to be a lot of stuff crammed onto it. Hence a high res is best so that the map can be zoomed in somewhat if one wants to take a closer look at smaller towns and such, not to mention that the higher res + a decent level of anti-aliasing makes things like city symbols and roads look a lot better (if the res and AA aren't high enough, you can really see some serious jagginess). I had the AA at 40% before, which at this resolution meant the program made 19 passes to render the image, but as I detailed above, that no longer works. Lowering the AA to 38% and keeping the same res lowers the number of passes to 18, which for the time being, it can handle.

    As I said, I wouldn't even mind if the render took several hours if it meant I could do something like 10,000x8000 with 50%+ AA on. Of course, I wouldn't do that often, but I'd like to be able to at all. Even just rendering it in 6000x4000 with 40% AA isn't SUPER high quality, and I can't do that anymore. And it concerns me that it's gotten worse since I first posted about it before; will it keep getting worse as I add more to the map?

    The other option is using the "Rectangular Section" option to render it out piece by piece, then stitch them together in Gimp. Each piece wouldn't have to have super crazy high res and AA for the total, reconstructed image to be high quality, so in theory this could work - kind of a pain but again, I wouldn't be doing it often. BUT, the problem is I haven't been able to figure out how to cut off the section when exporting so that it lines up when I go to put them back together in Gimp. So far when I've tried it, it's always a bit off, with a section missing or the parts having overlapping landmasses or some such.

    Come to think of it... anyone have any tips for that? How the heck do you precisely line up each rectangular section when exporting, so that they fit correctly when you put 'em back together?

    I'd love to see some kind of change to CC3 that would allow it to use more resources for rendering... but I don't know how feasible that is. Correct me if I'm wrong, but it is a fairly niche program, and the cost to implement that kind of improvement would have to come from somewhere.
  • Posted By: Saito SCome to think of it... anyone have any tips for that? How the heck do you precisely line up each rectangular section when exporting, so that they fit correctly when you put 'em back together?
    I never tried to do that, but I'd use coordinates to precisely define the rectangular sections. For example is you have your 6000x4000 and you want to export it in four parts, assuming the lower left corner is 0,0 (if not you can use the Origin command to put it there), when the prompt asks for the first corner and the opposite corner I'll type the following :

    1st corner opposite corner
    0,0 3000,2000
    3000,0 6000,2000
    0,2000 3000,4000
    3000,2000 6000,4000

    Note that, as far as I now, if symbols are partially on two or more sections, they will appear on none.

    You could also print with pdf creator (or equivalent) and use the tiling option in the print dialog with an overlap of 0%.
  • jslaytonjslayton Moderator, ProFantasy Mapmaker
    I usually use Photoshop when I'm lining up random image chunks, so I'm not sure how much of this applies to GIMP (most often I'm assembling together screen shots into larger images). My technique is to make sure that there's a discernable overlap (10% or more is usually sufficient) between pieces. Starting with a large blank canvas, I load one slice as the starting point. I then load each successive slice, adjust its opacity to 60% or so, slide it over the previous areas to ensure that the pixels line up perfectly, and then put the opacity back to 100%. It's the same basic process as a photomosaic, so any tools that you might have handy for that should work (Microsoft's Image Composite editor at http://research.microsoft.com/en-us/um/redmond/groups/ivm/ice/ might work, but I've never tried it with purely synthetic images).

    If you're going to be working with the image in GIMP anyhow, consider just exporting as high as you can go without AA turned on in CC3 and the do the AA yourself in GIMP. A Gaussian blur + resize will often look as good as the sort of AA that CC3 does (I vaguely recall discussion that CC3's AA just renders a higher resolution image and then resizes it smaller with something like a box filter).

    CC3 is unfortunately limited by its reliance on the basic GDI renderer in Windows; a different renderer such as GDI+ or OpenGL would allow for direct antialiasing of lines without having to do post-processing tricks. I gather that either of those options would require significant rewrites of the most basic elements of CC3.
  • 17 days later
  • Posted By: Joachim de Ravenbel
    Posted By: Saito SCome to think of it... anyone have any tips for that? How the heck do you precisely line up each rectangular section when exporting, so that they fit correctly when you put 'em back together?
    I never tried to do that, but I'd use coordinates to precisely define the rectangular sections. For example is you have your 6000x4000 and you want to export it in four parts, assuming the lower left corner is 0,0 (if not you can use the Origin command to put it there), when the prompt asks for the first corner and the opposite corner I'll type the following :

    1st corner opposite corner
    0,0 3000,2000
    3000,0 6000,2000
    0,2000 3000,4000
    3000,2000 6000,4000
    Thanks! I never knew you could select rectangular exports by coordinates; makes things a LOT easier. And I've figured out how to make them line up: as long as each exported section is the same resolution, they all line up perfectly in Gimp.
    Note that, as far as I now, if symbols are partially on two or more sections, they will appear on none.
    Do you mean that if the split point between two sections intersects a symbol, then that symbol will not be rendered? I haven't found this to be the case, unless I am misinterpreting you. Even if a symbol overlaps the edge of a section, it still rendered when I exported the sections.
    You could also print with pdf creator (or equivalent) and use the tiling option in the print dialog with an overlap of 0%.
    I actually tried this once, but I'm not really sure what to do... PDF creator has a huge list of options, and when "printing" to it, all I could get were moderately sized image renders of my map that didn't look very good... I'm really not even sure which options I'd need to change to determine what kind of resolution and quality the export will have. Bottom line is basically I have no idea how to use PDF creator in general, really, let alone as an export method for CC3. XD

    One new problem. Exporting via multiple rectangular sections DOES indeed work, now that I know how to do it properly, but now I'm getting this:
    image

    They are a bit subtle, but in the top-center of the image, you can see these stark "bands" separating the lighter blue sections from the darker blue sections. These show up along the top and/or bottom of each exported section. This ONLY happens when I export with the effects on, which makes me think it could be some kind of issue with the effects on the "Background" and "Sea" sheets messing with each other or something?
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