Maxwell Render | Official public forum

1. Excuse me, maybe repeatable question, but after some search i didn't found any clear answer: i'm modeling my studio in centimeters so that 100cm in Maya equals to 10m of real size, i.e. scale coefficient is 10.

What "Global scale coefficient" should i set in render globals? 10?

2. It was stated that MW is unbiased and kinda so realistic that users can just enter real life watt values for emitters for realistic lighting. Then there's a question arises: does anybody uses efficiacy higher then real values, and higher then 100(ideal emitter?)?
How does it correlated with "real-lifness" of rendering?

If you're modeling to scale, leave global scale at 1. Just set the correct unit in the Maya UI.

Maya incorrectly working with units other then cm, so i prefer to work in centimeters.

Well....i think i can assume that nobody using Maya with Maxwell...

If you are working in cm and the scale is correct (1m(real)=100cm(maya units)) everything should be ok with default scale.

Yes, I have never had any problems with scale in maya. Cant help you Joss, sorry.

If you are working in cm and set Maya to work with cm scene scale should be 1.

I've modeled studio, as stated before, 10 times smaller then real one. It's not real scale. Instead of 10x10m room, it's 100x100cm.
What i'm asking is what coefficieng should be set in renderGlobals: 10 or 0.1? Cause i read on the forum that somebody set 0.01 coeff in Max, and i'm confused totally.

Can please anybody from NL answer this?
And what about efficiacy of light sources?

I think global scale is a multiplier so if you want to change your 100cm to 1000cm you should set it to 10.

If your scene is 10 times smaller you need to make it 10 times bigger, therefore the global scale is 10.

The plug-in first converts all position information from the current Maya unit to meters. It then multiplies the positions by the global scale factor.

Some people on the Max forum are a bit confused because the old Max plug-in didn't automatically convert from the current Max unit to meters so they had to compensate manually by using the global scale. For example, if they had their scene set up in inches (which is the Max default), they had to use a global scale of 0.0254; if the unit was centimeters, they had to set the scale to 0.01. The new Max plug-in converts automatically as well, so they don't have to use the global scale like this anymore.

On the efficacy issue: I think there's a terminology problem here. Luminous efficacy is measured in lm/W and it has a theoretical maximum value of 683.002. Luminous efficiency is expressed as a percentage and represents the ratio between the total luminous flux emitted by a device and the total amount of input power. Being a percentage, efficiency has a maximum value of 100. Details: http://en.wikipedia.org/wiki/Luminous_efficacy .

Neither the plug-in, nor Studio will allow you to set an efficacy higher than 683, so you can't break physical laws this way. :) Just make sure that you get your values from a table which contains efficacy, not efficiency.

Mihnea Balta wrote:Just make sure that you get your values from a table which contains efficacy, not efficiency.

Mihnea is right here. However if you find tables showing efficiency instead of efficacy, you can make this small conversion easily.
efficacy = efficiency * 6.83