And now: Area lights!

General discussion about the development of the open source Blender

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ton
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And now: Area lights!

Post by ton »

New lamp type in current bf-blender CVS

http://www.blender.org/bf/rt1.jpg
http://www.blender.org/bf/rt2.jpg
http://www.blender.org/bf/rt3.jpg
http://www.blender.org/bf/rt4.jpg
http://www.blender.org/bf/rt5.jpg

Last 2 images rendered without shadow, just to show the subtle difference this lamp type makes. Not raytraced, just a good algo stolen from the radiosity module.

Demo files at download.blender.org/demo/test/

CVS log:
http://www.blender.org/pipermail/bf-ble ... 00953.html

Oh; and soft shadows render much nicer & quicker too. :)

dreamsgate
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Post by dreamsgate »

Oh, that is too sweet. I can't wait to play with that. :P

slikdigit
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Location: Northampton, MA (US)

Post by slikdigit »

Hi Ton, just built from cvs, I've got the following render:
Image
I wonder if you know what the horizontal lines are in the render, esp on the floor? I'm using 4x4 samples in the scene, upping the number seems to help a tiny bit (at the expence of rendertime) but didn't get rid of them. Any ideas?
PS (I actually like the lines- but I'm curious if some 'extreme' like scaling the light to high, scaling the scene too low, .... will cause such an artifact)

theeth
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Post by theeth »

Are you using the Jiter or Diter options?

Martin
Life is what happens to you when you're busy making other plans.
- John Lennon

slikdigit
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Location: Northampton, MA (US)

Post by slikdigit »

Yes. Here are some more images to see the effect of different options:
4x4 sampling, no buttons:
http://www.slikdigit.com/images/nobuttons.png
4x4 sampling, jitter only:
http://www.slikdigit.com/images/jitter.png
4x4 sampling, dither only:
http://www.slikdigit.com/images/dither.png
4x4 sampling, dither and jitter:
http://www.slikdigit.com/images/ditherjitter.png
4x4 sampling, dither, jitter, clipcircle:
http://www.slikdigit.com/images/ditherj ... circle.png
10x10 sampling, dither, jitter, clipcircle:
http://www.slikdigit.com/images/tenbyten.png
If you look closely at the last image you can see that the lines are still there, just that the constrast between them is greatly reduced.
I'd be glad to email you the .blend if you want to try a render on a different system. I just tried the build from ztonzy's thread- same result.
[edit] just changed "img' tags to 'url' - didn't mean to flood this thread with test renders. :oops: - looking at it seems like the dither is following some kind of regular pattern rather than being random.

ada89
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Post by ada89 »

Both image is 100% smaller than the actual render

Image
Weird thin line shadow on the mesh (1pas)

Image
Rendered with 16 pas without dithering and clip circle (different lighting)

@ndy
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Post by @ndy »

great!
when can we expect global illumination and hdri map support? ;)

.andy

theeth
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Location: Montreal
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Post by theeth »

@ndy wrote:great!
when can we expect global illumination and hdri map support? ;)
tomorrow, with fluid dynamics the day after, cranium jacks next week and global human network the week after.

Martin
Life is what happens to you when you're busy making other plans.
- John Lennon

Grendal
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Post by Grendal »

I don't know if i'm missing something, but is there some place i can download a binary of this new blender for a windows platform?

Thanks :)

JA-forreal
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Joined: Sat Mar 22, 2003 10:45 pm

Post by JA-forreal »

theeth wrote:
@ndy wrote:great!
when can we expect global illumination and hdri map support? ;)
tomorrow, with fluid dynamics the day after, cranium jacks next week and global human network the week after.

Martin
Hehehe. The new rendering tools are great Ton! At the rate that Blender is moving feature wise we may get so busy playing with the new stuff that we forget about asking for other features. Ton, you and the coding team already have added so many cool new tools. I may link to the org one day and find that you have added every feature that is possible to code into 3d app and then some.

"What's that I smell? Is it the smoke comming from their keyboards?"

Blend on!

ton
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Post by ton »

slikdigit wrote:Hi Ton, just built from cvs, I've got the following render:
I wonder if you know what the horizontal lines are in the render, esp on the floor? I'm using 4x4 samples in the scene, upping the number seems to help a tiny bit (at the expence of rendertime) but didn't get rid of them. Any ideas?
Hurms... looks like something is obscuring half of the samples consequently. If you can make a small simple scene for me with same
light setup, please! Just mail personally to me.

It looks like that you use a very large area light, which distributes samples quite some. All stuff to be tested... :)
But a replacement for radiosity it certainly won't become!

BTW, the dither is regular... only to be applied to minimize subtle banding, not to improve low sampling rates.

levon
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Location: adelaide

Post by levon »

this is ggod news, i was jsut wondering how much of this stuff is new and how much was from the 'traces' code?

and of the new code, how long ago did you start on the code, or what is the total time it took to code it?

now if only i didnt suck at modeling and texturing, ild be able to make some good art :o

GREAT WORK ALL THE TEAM
and happy newyear

ton
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Post by ton »

Area light easily overflows, this reveiled another shortcoming in Blender,
and that's the way how it clips light.

http://www.blender.org/bf/rt8.jpg

Thanks to a hint from Jandro, we now can do an 'exposure' correction as happens in Yafray already, which maps high intense light better to the visible RGB space. With identical lamp settings of previous image, this can be achieved:

http://www.blender.org/bf/rt7.jpg
http://www.blender.org/bf/rt6.jpg

CVS log:

Added improved exposure calculation
- based at 1.0-exp(-color) trick in Yafray. But to guarantee backwards
compatibility, and some more control, Stefano Selleri hacked a useful
formula for it.
- We now have 2 values to set in UI:
- "exp": the exponential correction value (0-1)
- "range": the light range that maps on color 1.0 (0-5)
- Using exp(x) (is e^x) we can much better prevent overflows from render, which are currently hard-clipped in Blender. Setting a small 'exp' value wil efficiently smooth out high energy and map that back to a color for display.
- total formula:
newcol= linfac*(1.0-exp(col*logfac))
(col, newcol are colors)
linfac= 1.0 + 1.0/((2.0*wrld.exp +0.5)^10)
logfac= log( (linfac-1.0)/linfac )/wrld.range
(wrld.exp and wrld.range are the button values)
- default setting: exp=0.0 and range=1.0 give results extremely close to
previous rendering.
- graph: http://www.selleri.org/Blender/buffer/Image1.png for 'exp' settings ranging from 0-1, and with 'range'=2

Thanks Stefano for the help!

ton
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Post by ton »

ada89 wrote:Both image is 100% smaller than the actual render
Ada89: can you also provide me this .blend file with the stripe error?
Thanks!

Grendal
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Joined: Fri Dec 12, 2003 4:06 pm

Post by Grendal »

please, anybody :( !! is there any way for me to download an "exe" for windows, of the blender w/ area lights, or is it only downloadable in source code form?

help!!

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