physical correct atmosphere with beamerlight

[hot chip]

hi guys,

here is example szene. In this szene is two normal Spot from Max (no ies-light).


left= normal spotlight <-> right = normal spotlight with physical-light shader from Mental Ray

download Max9 File: http://forum.german-mentalray-wiki.info/viewtopic.php?t=372

http://forum.german-mentalray-wiki.info/userpix/5_beamer_licht_small_1.jpg

[nisus]

HI Hotchip,

What are the advantages of both? When would you use one or the other?

nisus

[hot chip]

hi nisus,

the problem is, normaly in max have you standart light with inverse square or the max photometric light. This can you good see in a picture. At the beginning from atmosphere, have the photometric light more energy as the standart light.

fact a) The standartlight is faster as photometric Light but not so realistic. The attunation from the photometric light is more realistic as the standart light with inverse square.

fact b) i can´t put a map in a photometric Light color, only in the standart light.

the solution is, take a standart light and use the mr phycical light shade. Now you have the same qualitity as the photometric, but it is so fast as the stándart light and you can now use a Bit-Map for the light color, for creating a physical correct atmosphere beamer light.

[nisus]

so in the end, you got a fast rendering physical correct light (better than a standard light) where you can use a bitmap for projecting colors... cool!

why don't you youse the photometric lights?

nisus

[hot chip]

in normaly i use photometric-lights with ies-data for architectual visualization, but for special effekts it is good to have another ways. ;)

[moid]

Hello Hot Chip, could you please post the direct link to the max 9 file, I've checked the page you link to and I can't find a link to your max file on it. This looks very interesting, I assume you are generating the thin lines in the volume / beam by using a black and white bitmap?

Thanks very much for your help:D

[hot chip]

Hi moid,

you must only registered on the GMRF and then you can see this attachment to download the max 9 file. ;)

[moid]

Thank you Hot Chip, I have registered and am downloading the file now:D

[F3LIC3]

Hi hotchip!
Can you explain how you use the physical-light shader, because when I use it, it only renders black. Is there a trick or what?

Du kannst es mir auch auf deutsch erklären^^

[hot chip]

hi f3lic3,

please ask in the GMRF when you want the answer in german. I am answer only in english on this forum;) The physical_light shader needs very high value from 100 to 10000 or higher. The value can changed with the szene unit, i am use 1unit=1meter. Then is value 1=1 Candlelight/lux

[F3LIC3]

Can you please explain the values and give an example of how you set them, because I just can't get it to work...
I hope we are talking about the same physical_light shader, which must be unhidden?

[hot chip]

hi,

please go to the GMRF, and we can talk in german, because your motherlanguage is german and my. ;)

deutsch: geht bestimmt schneller zu erklären und dort gibt es Beispiele, auf die man sich beziehen kann :o

[moulder6]

Hi, hot chip!

As far as I see, you've understand MR lights, light shaders and volume shaders almost perfectly.
For some time I have troubles with all of them :(

Have an interior scene (max 9), which is lit by two omni lights which I'd like to make physically corect (mib_physical_light, mib_light_photometric and mib_cie_d - after unhiding them they don't work correct) stuff and add some volume light effects to them, while still keeping soft shadows.

Now that I downloaded your scene shown above It works. What shoud I say though is that I can't set it on my own.

What i did (look at the attachment) is creating mr Omni and then put the Light Shader from your physically correct light.

Would be glad if you give some directions of workflow (tutorial would be great) with creating a physical light source that uses IES and have folumelight aplied to it!

Thanks in advance!
Peter :)

PS. One more thing to mention. I have great problems with understanding German :(

[hot chip]

hi,

can you upload your interior scene, when we can looking for problem.

mfg
hot chip

[moulder6]

Well...
Thank you hot chip, but I suceed doing it alone! It was all, because of the units setup. Insted 1unit = 1meter i had set it 1unit = 1cm... Now I fixed it and everything works great...
The single thing which I'm not able to do is set those mib_photometric_light shader for it needs some kind of additional declaration which i have no idea how, and where to make :(
I can use max photometric lights, though I still need soft raytraced (area) shadows that's why i use mr_omni with light shader.
Any ideas or examples would be great!

Thanks again :)