Welcome to Fractal Forums

Fractal Software => Mandelbulb 3d => Topic started by: BadCRC on September 09, 2011, 04:21:58 AM




Title: Lighting change on the edges of animations
Post by: BadCRC on September 09, 2011, 04:21:58 AM
I have never been able to resole this.  When I create fly-through animations with Madelbulb 3D I get a light changes around the edges of the animations.  The middle of the animation looks fine but the edges has a dramatic light changes.  I have tried all kind of settings from "Light angles relative to object" in Global Light to the other forms of lighting like Positional light and Lightmap to name a few.  Nothing seems to fix it. 

I am not the only one that gets this.  Here is a random YouTube example, not one of mine that shows what I'm talking about. 
http://www.youtube.com/watch?v=3FoupqgbDkk

If anybody knows what the cause is or even the solution please let me know.

Thanks


Title: Re: Lighting change on the edges of animations
Post by: Syntopia on September 09, 2011, 04:23:56 PM
This is only a guess, but if you use the screen-space techniques in M3D for some of the lighting (the SSAO shadowing), I would expect edge artifacts, since screen-space techniques only take the visible geometry into account. Geometry moving out of view will no longer occlude nearby geometry.


Title: Re: Lighting change on the edges of animations
Post by: Jesse on September 09, 2011, 08:01:46 PM
My guess is that you meant the color changes of the object, what is quite common when zooming in or out.
That depends a bit on the coloring option you are using, but it is very hard to get totally rid of it.
Adjusting the Col. start and Col. end sliders for each keyframe relative to the histogram between the sliders is a way to reduce it.
And maybe not using the 'Color var. on Z' (set to zero position) might be better or easier to archieve this.

You have to keep in mind that there are not really absolute colors and even the shapes of the object can vary very much when zooming in, you see in 3d only one surface that gets nearer to the set when zooming in.  Even in 2d the color would change, but in 2d you have akways the whole cut, not only a surface.  So a stable color when getting closer is quite challenging and there might be better options to do so for animations, but i dunno  :-\


Title: Re: Lighting change on the edges of animations
Post by: BadCRC on September 10, 2011, 03:32:16 AM
You are most likely correct that it is the color that is changing since it is your program.  I will try the Col. start and Col. end suggestion you made.   The reason I thought it was lighting is that I see the same phenomenon when I use "Use a map for the diffuse color" option and it does not use Col. start/end.

Why does it mostly happen around the peripheral parts of the image? 

Thanks for the help.


Title: Re: Lighting change on the edges of animations
Post by: Jesse on September 10, 2011, 08:54:38 PM
You are most likely correct that it is the color that is changing since it is your program.  I will try the Col. start and Col. end suggestion you made.   The reason I thought it was lighting is that I see the same phenomenon when I use "Use a map for the diffuse color" option and it does not use Col. start/end.

The map option uses always 2 values, if you use the default Coloring options you get the default 'smooth iteration' for one dimension (unscaled, that is why there is no start/end sliders), and 'orbit trap' as second dimension.
When the smooth iterations changes (it is somewhat biased to lower these changes on zoom, but that depends strongly on the formula combination - so changings mostly happens) the map location and with it the colors are changing too.
You might try the other 'Coloring' options in the main windows tabs, though most have to strong or not enough gradients, depends also on the formula.

Quote
Why does it mostly happen around the peripheral parts of the image? 

Not sure what you are meaning with peripheral parts, it changes the most with zoom factor, the distance to the object where raymarching stops.  That varies with zoom and also on the distance if 'Vary DEstop on Z' is checked.


Title: Re: Lighting change on the edges of animations
Post by: knighty on September 10, 2011, 11:04:25 PM
BadCRC: Just to be sure: Are you using SSAO or DEAO (in ambiant shadows)?

 


Title: Re: Lighting change on the edges of animations
Post by: BadCRC on September 11, 2011, 11:09:53 AM
Quote
Not sure what you are meaning with peripheral parts

OK.  Look at this video for example, from 39s to 50s you can see an exaggeration of what I am talking about.
http://youtu.be/SkxTdEWCvds?t=39s

Look at the darken crevasses around the peripheral of the frame get illuminated as the camera moves in.  I wonder why the color/light is effected so differently around the edges than in the middle of the frame?

Quote
Just to be sure: Are you using SSAO or DEAO (in ambient shadows)?

I use SSAO.


Title: Re: Lighting change on the edges of animations
Post by: Jesse on September 11, 2011, 10:53:37 PM
Ok, a typical misunderstanding.. now its clear, thought with 'edge of animations' you meant the start or end of an animation, not the edges of the frame images  :)

So Syntopia was right, my explanation is good for another question.

The SSAO uses only the Zbuffer to estimate a shadow function, structs outside the image cannot be taken into account.
You can lower this artifacts a bit with the 'Threshold to 0' option, useful for thin unconnected structs.
Or use the DEAO function (these functions are in the 'post processing/ambient shadows' tab) that does not use the ZBuffer, but is mostly slower.


Title: Re: Lighting change on the edges of animations
Post by: BadCRC on September 12, 2011, 10:48:47 PM
Solved.  DEAO did the trick.  Thanks to Syntopia, knighty and Jesse for your insight.