[Petero]

Hi,

yes Formz has many options to genrate sphere geometry. so from what i understand, by assigning the emitter material to a sphere, the ies data is given a default orientation, and that once i have testes that, i can pivot my shere to get what i want?

i have done a trial with both a sphere and a flat rectangle assigning the same emitter material to both.
i will post results in a few images.

[Half Life]

It should be that simple assuming the plugin supports it -- as I say that is how it works in Maxwell Studio and the Sketchup Plugin.

You should always use a sphere for IES unless your plugin specifically calls for something else.

BTW -- does the new Bonzai3D plugin and manual have application for FormZ as well?

Best,
Jason.

[Petero]

Ok the test is coming- i went to ERCO website and downloaded this
erco_compact_hit

a basic down spot. i got the 3ds data as well as IES the IES I applied to the circular flat objst that i assume is mean to be the emiiter surface in their 3d model. i then also applied the same emiiter material to a sphere and flat rectangle and am doing a maxwell render of all three.

ok, i just realised that i cannot attach an image easily here...so till i figure that out, i'll need to keep results to myself!!!

btw, all three work, but the light coming off the Erco 3ds geometry (it'a a flat polygon, maybe 20 sides) is giving off alot more noise during the render than the other two; I don't know if this is because there is a 'ring' around the endge in 3d space(part of the light 3d geometry i imported)... i'll have to test it without the ring object on.

[Mihai]

If you're using the actual light fixture model, then you don't have to use the IES. The IES light profile is ment to mimic how the light shines through that fixture. So just apply a regular emitter to what is supposed to be the light bulb in that model.

[Petero]

Mihai,

thanks for that piece of information. the erco 3d model wasn't as complex as you suggest- just a ring with a flat polygon. the actual fixture is a lot more complex- with a reflector etc... i'll need to see if i can find a site with fixtures that you describe.

hey can I get permission to upload test images in my posts?? that would be cool. i am a licensed user, + 1 node.

thanks,

peter

[Half Life]

The important thing to know here is the IES material is not an emitter in the traditional Maxwell sense -- often times it will render completely black while still giving off light... this is normal (because of scale/shape variations between the actual scale/shape of the recorded "light fixture" and the sphere the material is mapped to).

Applying an IES material to anything but a sphere will confuse the issue because the IES file is not (strictly speaking) a record/model of the emitter/light fixture -- it is a record/model of the light falloff within a IES testing "Integrating Sphere"... the emitter/light fixture is only incidental to that recorded data as far as how Maxwell will render it.

Here's some links for "Integrating Sphere" measuring systems so you can see the testing environment that generates the data:

http://www.lightingsciences.com/wp-cont ... 3-2010.pdf

http://www.pro-lite.uk.com/File/integra ... meters.php

When we are making the sphere for Maxwell it has nothing to do with the final desired light fixture -- what we are recreating is the "surface normals" of the "Integrating Sphere" testing environment used to make the IES file, so that the data contained in the IES file can be accurately projected.

Best,
Jason.

[pipcleo]

All my tests with ies have proved pretty fruitless.
The intensity of the light is always just too weak......using the eco supplied ies and other non supplied ies data.
Even using ies in a 'square' room with no other light source in a scene provides insufficient output...

[Petero]

i guess i am more interested in the IES information because it can give shape to the light dispersion that is specific to certain fixtures, and add a sense of realism to renderings. as for output power, i'll probzably end up 'cheating' and just crank up the power in the mutilight settings till i get what i like.

-Peter

[numerobis]

...hey can I get permission to upload test images in my posts?? ...

you have to upload your image to any image hosting service and add the resulting link using the [img]-tag

You can use one of these (e.g.):

http://tinypic.com/
http://www.yr8.de/
http://imageshack.us/

[Half Life]

All my tests with ies have proved pretty fruitless.
The intensity of the light is always just too weak......using the eco supplied ies and other non supplied ies data.
Even using ies in a 'square' room with no other light source in a scene provides insufficient output...

Could you create a "square room scene with IES" sample MXS file and post it? If I could look at what is going on in the file I may be able to help you get better results.

As Peter says, IES is very useful to gain additional realism without the need to model fixtures -- this is particularly true for "off-camera" lighting where you only need to see the resulting light, if you need to see the actual light source itself "on-camera" than IES can be less useful.

Best,
Jason.

[Petero]

images
this is the geometry:
[/img]

[Half Life]

If you use anything but the sphere you may not get accurate results.

[Petero]

this is the multilite result in a white box(order left to right corresponds to previous post)

notice more noise on right(the 24 sided polygon)
Hey what's with the little spot shadows on the floor????? there is NO floating geometry to cast those- i assume a sort of artifact....

[/img]

[Half Life]

The plane(s) are giving bad intensity due to improper shape/normals... the shadow is due to the light falloff of the measured IES data -- it is not faulty, it is meant to be that way.

Use the sphere.

[Petero]

and just to show that i am trying to enter the testing maxwell spirit that Jason explicitly recommends, her eis a test of emitter polygons- they go from 3 sided on left to 22 sided on right progressively- no ring geometry, and the noise increase is clear ...

thanks for your speedy responses, Jason!!!

[/img]