OTOY Forums

Hi Radiance,

For bright exterior lighting, the daylight system is great, but the problem I encounter is that the cylinder or section of sphere on which I map a panoramic view of the environment using a diffuse material, casts a shadow on the scene, allowing limited angles for the sun position (Sun around 12:00).

Is it possible currently to disable shadow casting on a material ?

If it isn't, would it be possible to add as a feature in a next release of Octane ?

Thank you in advance.

Philippe.

Good request.

Hi,

Although it's not common in physically based renderers to implement these (as they have no basis in reality),
we can add it to our list for beta3.

Radiance

Nice to hear that
Its probably the most used trick for rendering interior archviz
Backplate without shadows mapped on a mesh + physical sun

But you are right, its more a post-prod thing than something in reality

Yeees! Thanks a lot, it is very useful !

Usually what is a good solution is to render the background pure black with alpha and then composite in PS... it could be an option on export, let you choose to replace the background with black (as long as there are no residual from the original background)... I bet it's much easier to implement, and it doesn't cause any paradox in the space-time continuum etc...

@Proupin : your proposal is an interesting and useful feature, it is complementary but it is not the same use.

Using a visible and renderable background not casting shadow on the scene is necessary to adjust the scene in real time and it will be even more necessary when Octane will support animation. With your suggestion, for an animation I fear that we would have to do a camera tracking process of the sequence rendered with Octane to add a background in the 3D application and composit the background !

Oh yes, you are right, I was thinking on the different possibilities, and yes it is not a matter of one or the other for sure... not only animation would be a problem, but also whenever the background is to be seen in reflections and through transparent objects

I then agree both are necessary; would it require also a new material property perhaps? one where lighting does not affect the texture ("self-illuminate" in 3ds max)

EDIT:
Other features widely used (sorry if I'm getting off-topic here):
independent "slots" for background, reflections, refractions, and illumination
only seen in reflections and/or refractions (perfect for those window reflections)
etcetera...