Re: Mtoa vs Sitoa vs Penumbra

[Stephen Blair]

Hi

Those parameters do the same thing and have the same meaning in any of the
Arnold plugins.

In general, the mailing lists are customer-only.

Thanks

Stephen
Solid Angle Support

On Mon, Nov 30, 2015 at 6:46 PM, Sebastien Sterling <
sebastien.sterl...@gmail.com> wrote:

> Thanks Steven, am of to digest all this :)
>
> I know that they both have exposure and intensity.
>
> the impression i got in sitoa is that you can leave exposure at it's
> default, and just ramp up the intensity, as explained in the guide
>
> "If you are not used to working with exposure in the lights, you can
> simply leave the exposure parameter at its default value of 0 (since 20 =
> 1, the formula then simplifies to: color * intensity * 1)."
>
> I get from this that exposure is for people who like to work with camera
> terminology.
>
>
> In Mtoa, it feels like "Exposure" is a far more important parameter. i was
> just concerned if this affected physical accurate lighting in any way. in
> the past i've seen both schools of thought clash.
>
> Is there still an Arnold list to put these kind of questions too ? and if
> so, how does one get an invite ?
>
>
> Thanks again for the full answer !
>
>
>
>
> On 30 November 2015 at 22:26, Stephen Blair 
> wrote:
>
>> Hi
>>
>> The only differences in a default spot light are the default
>> spot_light.cone_angle and the spot_light.samples.
>>
>>
>>- MtoA sets the cone_angle to 40 (the Arnold default is 65)
>>- SItoA sets the samples to 2 (the Arnold default is 1)
>>
>>
>> Here's the non-default settings from ASS files exported from Maya and
>> Softimage:
>>
>> # MtoA default
>> spot_light
>> {
>>  name spotLightShape1
>>  cone_angle 40
>> }
>>
>> # SItoA default
>> spot_light
>> {
>>  name Spot.SItoA.6000
>>  samples 2
>> }
>>
>> And here's the Arnold defaults:
>>
>> # Arnold defaults
>> kick -info spot_light
>> node: spot_light
>> type: light
>> output:   (null)
>> parameters:   33
>> filename: 
>> version:  4.2.11.0
>>
>> Type  Name  Default
>>     ---
>>
>> POINT[]   position  0, 0, 0
>> POINT[]   look_at   0, 0, -1
>> VECTOR[]  up0, 1, 0
>> FLOAT radius0
>> FLOAT lens_radius   0
>> FLOAT cone_angle65
>> FLOAT penumbra_angle0
>> FLOAT cosine_power  0
>> FLOAT aspect_ratio  1
>> ENUM  decay_typequadratic
>> MATRIX[]  matrix
>> RGB   color 1, 1, 1
>> FLOAT intensity 1
>> FLOAT exposure  0
>> BOOL  cast_shadows  true
>> BOOL  cast_volumetric_shadows   true
>> FLOAT shadow_density1
>> RGB   shadow_color  0, 0, 0
>> INT   samples   1
>> BOOL  normalize true
>> BOOL  affect_diffusetrue
>> BOOL  affect_specular   true
>> BOOL  affect_volumetricstrue
>> FLOAT diffuse   1
>> FLOAT specular  1
>> FLOAT sss   1
>> FLOAT indirect  1
>> INT   max_bounces   999
>> NODE[]filters   (empty)
>> FLOAT[]   time_samples  (2 elements)
>> INT   volume_samples2
>> FLOAT volume1
>> STRINGname
>>
>>
>> A light has Intensity and Exposure parameters, both in MtoA and in SItoA.
>>
>>
>>
>> Thanks
>>
>> Stephen
>> Solid Angle Support
>>
>> On Mon, Nov 30, 2015 at 4:50 PM, Sebastien Sterling <
>> sebastien.sterl...@gmail.com> wrote:
>>
>>> Hey List have been messing around and comparing Mtoa with Sitoa
>>>
>>> Is it just me or is Penumbra a very different thing in each versions ?
>>>
>>> sitoa feels like you start from scratch, absolute zero, and work up,
>>> Mtoa feels like you just walked into a previously saved preset. it looks a
>>> little nicer, but i can't shake the niggling feeling that it starts from a
>>> stylized/physically inaccurate base.
>>>
>>> Does anyone know how to soften the falloff on a spotlight ?
>>>
>>> Cause Penumbra doesn't seem to do that in Mtoa.
>>>
>>> and is exposure in the Arnold settings in Mtoa = to The light intensity
>>> in Sitoa ?
>>>
>>
>>
>

Mtoa vs Sitoa vs Penumbra

[Sebastien Sterling]

Hey List have been messing around and comparing Mtoa with Sitoa

Is it just me or is Penumbra a very different thing in each versions ?

sitoa feels like you start from scratch, absolute zero, and work up, Mtoa
feels like you just walked into a previously saved preset. it looks a
little nicer, but i can't shake the niggling feeling that it starts from a
stylized/physically inaccurate base.

Does anyone know how to soften the falloff on a spotlight ?

Cause Penumbra doesn't seem to do that in Mtoa.

and is exposure in the Arnold settings in Mtoa = to The light intensity in
Sitoa ?