Big Render bug - wrong colors

[mondaymorninglunatic]

Hey there,

I wanted to make very huge render image. I made a sample for how it schall look. Notice the bright blue color of the structures: http://imageshack.us/photo/my-images/594/samplee.png/

The tiles but then have different colors: http://imageshack.us/photo/my-images/69/bigrender4x04y01.png/

the project File is this: http://www.speedyshare.com/files/30168981/ikosa_box_surface_20k_8x8_test_test.big
Try out the parameters with a normal size resolution. It should look like the sample.

why is that so?
Am I doing something wrong?
And btw does anyone like to help me rendering the whole thing?

please help!

[knighty]

Looks like a bug, maybe related to floating point number precision and DEAO. After setting "size factor" to 20 and 30 instead of 40, it have given "correct" result.
Nice rendering . If you want it to be more detailed, uncheck "Scale DEstop to keep color and detail level". You can also set a higher "raystep multiplier" (0.5 or even higher values) to speed it up a little bit.

[mondaymorninglunatic]

oh thank you!
I will try that out.
right now my pc is busy. I am rendering an 1080p animation around that same thing. A friend is also helping me to render the frames. We also made a little vvvv-patch to get statistics. Who's pc is faster and stuff. Very funny. When the animation is ready i will show here.

and the rendering. Well it is an ikosahedron formula (iteration count 2) with an amazing box formula (iteration count 1) afterwards. it's pretty cool for it creates ikosahedron-ish shapes that are never repeating. I guess its because icosahedrons and boxes don't fit really. You should try it out - i got some amazing renderings with it.
( i don't really like tooo smooth and round fractals, because fractals are too often just round.)

some renders from that formula combination:
http://shapesforthoughts.tumblr.com/

click on the images, they're relatively highres.
(i also have the real-hires pictures somewhere on my computer if there's interest)

[Jesse]

Hi mondaymorninglunatic,

can you just attach the *.big file to one of your postings, because the downloading does not work for me!

Maybe i can figure out then what is the problem with this, thx...

[Sockratease]

can you just attach the *.big file to one of your postings, because the downloading does not work for me!

I just added .big to the list of allowed file extensions, so it should work if anybody wants to try.  Those are small parameter files, not huge image-bearing files, right?  I never tried one so don't know.  Either way the file size limitations of the forum's attachments still apply.

Hope that helps.

[Jesse]

I just added .big to the list of allowed file extensions, so it should work if anybody wants to try.  Those are small parameter files, not huge image-bearing files, right?  I never tried one so don't know.  Either way the file size limitations of the forum's attachments still apply.

Hope that helps.

Ah yes, did not thought about file extension restrictions, but it could always be zipped if it would fail otherwise.

The 'big' files are just the parameters with some additional values, really short.

Thank you Sockratease! 

[mondaymorninglunatic]

here is the file.

i retried it in the meantime with a global resolution of 10,000x10,000 pixels. there is no bug with the colors.
very strange.

[Jesse]

Thank you, i will have a look at it.

In the meanwhile, have you tried a tile more from the middle of the image if this is that dark too?
Because the left upper corner is very dark... (of course there could be problems with the ambient shadows or the dynamic fog anyways, can't say it yet)

[mondaymorninglunatic]

yes i tried different tilings tiles (what is the right word for that?).
It's all dark.

I just now tried a completely different rendering and i had the same bug when switching to 20.000x20.000 global resolution.
very strange.

ah btw. main renderding and hard shadows looked all normal. But when the ambient shadows were rendered the colors went bad.
Seems like the ambient shadows is the problem with very huge resolutions.

[Jesse]

You are right, it is the ambient occlusion!
To limit the calculation length for the DEAO i calculate somewhere: Sqrt(Sqr(width) + Sqr(height))
but did not recognized that up to the sqrt all is calculated as integer, so if
Sqr(width) + Sqr(height) becomes bigger or equal then 2^31 there is an overflow.

For a square image format, 32767 would be max for width and for height (excluding aa, so multiply the big render sizes with aa).
 

I try to get the update as soon as possible online.

[knighty]

32768^2 gives 1Gigapixel and it's still not enought!? 

MML: very nice rederings! I'm sure you'll find blobs' Eye candys interresting.

[mondaymorninglunatic]

wow they're cool!
btw when i couldn't render the actual image i rendered an animation of the same thing.

<a href="http://www.youtube.com/v/-2MVyQzEj2M&rel=1&fs=1&hd=1" target="_blank">http://www.youtube.com/v/-2MVyQzEj2M&rel=1&fs=1&hd=1</a>

there's a 720p version also available soon on vimeo. (made the vid about a 100 bits/s to big so i have to encode a new version).

i also have a 1080p version if there is interest.

[knighty]

 

[Jesse]

Think i forgot a THANK YOU  , mondaymorninglunatic, for this bug report.
Else it would not be possible to get rid of these issues, one person has not the time to test all possibilities.

Nice video too!

[mondaymorninglunatic]

thank YOU! Now I can go on rendering my huge picture

and yeah i also like th video. Still a bit short unfortunately. Maybe there will be a longer one later.