HRI corona PARA CINEMA 4D

[corona]

Hello! This mini tutorial is for the CINEMA 4D crown - ALPHA V6. I had a problem with hdri in cinema 4d following the step by step of some tutorials that did not work, so I will summarize a step by step that went wrong and another that worked for me

wrong:
create a "sky"> create a light material of corona material> apply hdr to texture> apply material in the "sky"


right:
create a "sky"> create a new material crown> open the diffuse tab> apply hdr to the texture> apply material in the "sky"

as the corona for 4d cinema is in development maybe correct that!

[TomG]

Actually the tutorial is correct :) An HDRI in the Diffuse should NOT be used (it was the only way for it to work a long long time ago, but it is now not the correct way - the correct way is a CoronaLight material with the HDRI in the Texture slot, applied to a Sky, just as shown in the video).

If you have a scene or a situation where that did not work, then that could be a bug - please let us know more information about what did not work, share screenshots of the scene set up, and the material setups etc. On Corona versions, I strongly suggest keeping up with the latest daily builds, as those have the most features, there have been many changes since Alpha 6 for sure!

Also, your user name may be rather confusing, would be a good idea to change that, otherwise users may believe you are associated with the Corona team, ty for understanding!

Thanks!
   Tom

[Nejc Kilar]

@TomG,

Do you have any insight into why the diffuse method is wrong with the newer versions? I'm just asking because I thought the sampling algorithms don't really care...

Thanks!

[TomG]

The technicalities of it would be one for the devs to answer. On the logic of it, as a user, it makes more sense to me that being a light source, it would use the LightMtl.

In the case of localized light sources (e.g. the screen of a TV set), sampling is much more efficient from a LightMtl than from the Self-illumination slot of a regular material (in Max as well as C4D) so I would guess that behind the scenes there is some difference in how those materials can be sampled.

Either way, having one standard is good, and the LightMtl is the standard that was settled upon :)

[houska]

Do you have any insight into why the diffuse method is wrong with the newer versions? I'm just asking because I thought the sampling algorithms don't really care...

Imagine the sky as an infinitely large sphere. Maybe then it makes more sense why diffuse is incorrect.

Diffuse only says how much light will be reflected using a diffuse reflection. This does not make sense with the sky, as it doesn't reflect the light, but rather emits it (ofc, this is meant conceptually and not counting atmospherical scattering).