Logo by Fiery - Contribute your own Logo!

END OF AN ERA, FRACTALFORUMS.COM IS CONTINUED ON FRACTALFORUMS.ORG

it was a great time but no longer maintainable by c.Kleinhuis contact him for any data retrieval,
thanks and see you perhaps in 10 years again

this forum will stay online for reference
News: Check out the originating "3d Mandelbulb" thread here
 
*
Welcome, Guest. Please login or register. December 15, 2019, 02:09:58 PM


Login with username, password and session length


The All New FractalForums is now in Public Beta Testing! Visit FractalForums.org and check it out!


Pages: [1]   Go Down
  Print  
Share this topic on DiggShare this topic on FacebookShare this topic on GoogleShare this topic on RedditShare this topic on StumbleUponShare this topic on Twitter
Author Topic: Idea- an intermediate file for image tweaking  (Read 2435 times)
0 Members and 1 Guest are viewing this topic.
Tglad
Fractal Molossus
**
Posts: 703


WWW
« on: March 25, 2010, 12:30:26 AM »

When making images I find that getting the colour palette right takes a lot of trial and error, so it lead me to an idea.
Every pixel on an image can be calculated as baseColour + scale*colourAt(spectrumIndex)

So what would be really great would be if the renderer (which may take an hour on a high detail shot) saved to an intermediate file which contained 3 images, a baseColour image, a scale image and a spectrumIndex image. It would then be possible to adjust the spectrum in real-time and get the colours just right before saving to the final jpg. Anti-aliasing can be dealt with by just thinking of it as a higher res image.

You could take this idea further, for example, if you saved out the z-depth as an image then you could apply and adjust fog in real-time. You could add depth-of-field blur and tweak it in real time, you could even add a fake form of GI that puts crevices into shadow.
If you also considered the formula to be +lightScale*lightColour  and saved out an image of lightScale then you could adjust the strength and colour of the light in real time.

In fact, such image processing could be a separate application and used by any of the fractal generating programs out there, provided they create an option to export in this format.
I would write this myself, but sadly lack any decent knowledge of rendering, image formats etc  cry
Logged
reesej2
Guest
« Reply #1 on: March 25, 2010, 02:28:01 AM »

I love the idea, but someone with more GUI experience than I will have to take it up.
Logged
makc
Strange Attractor
***
Posts: 272



« Reply #2 on: March 25, 2010, 09:01:27 AM »

typically you would need to generate just two images, normals and z-buffer. this way, however, you loose deep shadows; you could re-trace using z-buffer, but there you only have half of information (no knowledge of hidden surfaces shape). which is why I was digging into isosurfaces lately wink
Logged
Tglad
Fractal Molossus
**
Posts: 703


WWW
« Reply #3 on: March 29, 2010, 03:38:30 AM »

That sounds like all the more reason to not use just 2 images. It's not like the size of the intermediate file is of great importance.
If the shadow casting is done in the main package, then the secondary package would be able to apply tweaks without tracing any rays. With simple combines it could tweak in real-time-
- the colour palette
- the colour and brightness of the light(s)
- the fog settings
- depth-of-field blur settings
- screen-space ambient occlusion (http://en.wikipedia.org/wiki/Screen_Space_Ambient_Occlusion) settings
- the ambient light level

Animations due to colour cycling, or a fog coming in, or a light growing (e.g. sunrise) etc would be so fast to render they could probably be real-time.
Logged
makc
Strange Attractor
***
Posts: 272



« Reply #4 on: March 29, 2010, 10:37:43 AM »

normal maps give you an ability to alter light direction. but you must not have real shadows then, or else an image would look broken.
Logged
Jesse
Download Section
Fractal Schemer
*
Posts: 1013


« Reply #5 on: March 29, 2010, 12:29:52 PM »

Good idea, i know about at least one program that already uses it  wink

(in the download section)
Logged
Tglad
Fractal Molossus
**
Posts: 703


WWW
« Reply #6 on: March 29, 2010, 01:11:05 PM »

Really? Mandelbulb3d does that? Awesome, I'll definitely have to try it out properly now.

I know Trafassel's Gestaltlupe program (http://github.com/trafassel/Gestaltlupe) does something along these lines, and gets some great depth of field blur from it.
Logged
Jesse
Download Section
Fractal Schemer
*
Posts: 1013


« Reply #7 on: March 29, 2010, 02:18:22 PM »

You just have to store all informations, the coloring and lighting are based on.
So for the color, i store only the smoothed iteration count (normalized to a 16 Bit value between minIt and maxIt) to generate along with the palette and the projection on it the new colors... also after calculation.
If the bulb is iteration count limited, then alternative the local gradient can be used for coloring.

And so with other values like normals, ambient- and hardshadow.

This is a great benefit i would miss, although other programs might have more options and higher quality.
Logged
Pages: [1]   Go Down
  Print  
 
Jump to:  

Related Topics
Subject Started by Replies Views Last post
UF 5 Sculpture file Parameter Files titia 0 3500 Last post July 24, 2008, 12:58:41 PM
by titia
Save 3d file Mandelbulb 3d scheven_architect 5 1967 Last post May 07, 2011, 07:42:38 AM
by Don Whitaker
inserting intermediate keyframes along the parameter splines Mandelbulber huminado 0 968 Last post November 25, 2011, 07:03:16 PM
by huminado
Read Me File Tuts / Reflective Diffs/100 % Mirroring Excercise / Image load Help & Support Balok 3 170 Last post January 19, 2017, 10:53:57 PM
by DarkBeam
Abox minR2 tweaking frag Amazing Box, Amazing Surf and variations mclarekin 0 410 Last post July 26, 2017, 03:18:00 PM
by mclarekin

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines

Valid XHTML 1.0! Valid CSS! Dilber MC Theme by HarzeM
Page created in 0.112 seconds with 27 queries. (Pretty URLs adds 0.006s, 2q)