Translucency Problem

[HeadlessBill]

I'm working on my image for the X-mas contest. And I'm running into problem. If you note the image below, there are certain parts of the candles where the translucency is not working properly (It's visible in the reflection on the table, too). I've tried changing materials, checking normals, altering the light source creating the translucency, but everything I try gives me the same results. Suggestions, work-arounds, comments. I can make a larger render if necessary.

 

[HeadlessBill]

Here is a closer larger image of the problem I'm talking about.

 

 

Oh, I guess I should add: I'm using A:M 10.5 for OSX on a 867MHz PowerBook.

[hypnomike]

I'm no expert (understatement) on translucency but further info may help.

 

What type of light are you using inside the candles?

 

Are the coloured cylinders the candles or are they glass covers with the candle illuminating from below?

[HeadlessBill]

The colored tubes are acutally the candles. Since the tops of the candles are not going to be in the final image (because I'm having problems creating something that I'm happy with), I didn't model tops to the candles. In the images you see here, I was using bulbs. When I changed the lights all to kleigs, the problem went away, but once I added any bulbs back to the scene, the problem came back. Maybe a bug?

 

Anyhow, by using a combination of kleigs with bulbs has helped minimize the effect, but you can still kinda see it.

 

[hypnomike]

Yes I see what you mean about the image, in the original parts of the candles seem to be letting less light through.

 

I can't think why, does anyone else reading this have any idea what is happening here?

 

You may want to see if you get further feedback John and send this to hash support if you get no joy.

 

Good luck.

[ypoissant]

I'm reading this topic since the beginning but I don't understand what is the problem. You seems to both see the same problem. Could you explain in further details?

[wwoelbel]

Yves;

 

The thing that "I" am seeing is a weird stripe thing. Look at the green candle in the second image. Notice the much darker stripe vertical on the front left (as you face it)? My question would be - are you using any decals? The edges look like decal wrap.

 

Bill

[hypnomike]

Yeh.. I'm pretty sure that's what he was drawing our attention to.

 

It took me a while to figure it out as I didn't fully understand what he was aiming for.

 

You could be onto a winner with decal wrap.

[ypoissant]

I observed that stripe too. But thought that was intensional. I'm not too good at speculating. I need very precise description of the problem, refering to precise spots in the images. Otherwise, I can see several places where I would not do it that way.

[HeadlessBill]

I'm sorry I confused everyone. I had debated with myself over marking the images to show the problems. I guess I should have. My faux pas.

 

wwoelbel & hypnomike, yes that is what I'm trying to point out, and no, I'm not using decals.

 

Anyhow, putting a klieg inside the candle, aiming straight up seems to help minimize the problem. So far, from my brief testing, the problem only seems to mainly occur when there is a bulb light in the scene. I will try to play around with it some more later, but am concentrating more on trying to get the image done for the image contest.

 

yves, as a person that has always been in awe of what you've done with A:M, I'm curious to know what I've done differently.

[ypoissant]

Yves, as a person that has always been in awe of what you've done with A:M, I'm curious to know what I've done differently.

Everything

 

You did nothing wrong. My point is we all have very different goals when we do a project. The end product is the result of the decisions we take to reach our goal.

 

So unless you are very specific about what you consider wrong in your render, I cannot say for sure if something is the result of a concious design decision to render a specific mood or something else that went wrong. I then have to project my own goals into what you are trying to achieve and this is very probably not the same goals as yours.

 

For instance, until you specifically pointed to this stripe, I was not sure if that wasn't a design decision to get a particular specular effect.

 

Given the same topic, two designers will choose very different set of design decisions. Fortunateley, that is what makes the monthly contests interesting.

 

On a purely technical POV, have you tried using the ambiance intensity setting to achieve the wax SSS you are trying to get? You could either do that with a gradient conbiner which controll the ambiance intensity property or an ambiance intensity decal.

[zandoriastudios]

http://www.hash.com/forums/index.php?act=A...e=post&id=18369

 

check out this thread for a different technique.

 

Right now it appears that one side of the cylinder is being lit from a light source on one side and exhibiting translucency on the back side, leaving a sharp edge at the terminator. Translucency in A:M doesn't work exactly like you expect from the real world (yet)...

 

J Griffins technique of material effectors is the best work around for your situation.

[HeadlessBill]

Yves, I did play a bit with ambiance before I started playing with translucency. But I felt it looked 'flat' compared to translucency, plus I kinda liked the speckled look I was getting from translucency. Currently, I am using a gradient combiner to control the amount of translucency on the candles. After the contest, I may play around with a combination of both. And speaking of playing...

 

Will, thanks for the link and the candle image it connects to looks good. Nearly the look I'm trying to get. But, I cannot find the topic you are refering to. I've done searches for 'material effectors' and 'Griffins', but am having no luck.

 

I need to quit working on this thing, though, and actually do my art design and sound design homework. But between work, school, wife and life, I don't have much free time to play with this thing before the contest deadline.