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 <stephenrbl...@gmail.com> 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: <built-in>
> version: 4.2.11.0
>
> Type Name Default
> ------------ -------------------------------- -----------------------
>
> POINT[] position 0, 0, 0
> POINT[] look_at 0, 0, -1
> VECTOR[] up 0, 1, 0
> FLOAT radius 0
> FLOAT lens_radius 0
> FLOAT cone_angle 65
> FLOAT penumbra_angle 0
> FLOAT cosine_power 0
> FLOAT aspect_ratio 1
> ENUM decay_type quadratic
> MATRIX[] matrix
> RGB color 1, 1, 1
> FLOAT intensity 1
> FLOAT exposure 0
> BOOL cast_shadows true
> BOOL cast_volumetric_shadows true
> FLOAT shadow_density 1
> RGB shadow_color 0, 0, 0
> INT samples 1
> BOOL normalize true
> BOOL affect_diffuse true
> BOOL affect_specular true
> BOOL affect_volumetrics true
> 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_samples 2
> FLOAT volume 1
> STRING name
>
>
> 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 ?
>>
>
>
