IPR & Final render differences

[Nejc Kilar]

Hello,

It seems like I have another bug to report. I hope its not a repost.

There is a difference in the image when working with the final render compared to the IPR. It appears that when geometry is a bit troubled (but still works fine in the viewport / final render) the IPR just looses its cool. :)

Generally what appears to be happening is that some materials just produce odd reflections and they don't respect some of the material parameters like glossiness etc...

It very much looks like a phong issue to me.

Attached is the screenshot and the file has been submitted through the helpdesk.

Again, I hope its not a repost :)

Thanks!

edit: The IPR is on the right, the final frame on the left.

[burnin]

Noticed this some time ago (post here)
observe table in lower right corner

I assumed not everything is described under: Are there any differences between regular and interactive rendering?

n Corona Renderer, final frame rendering and Interactive Rendering (IR) are handled by the same engine. In fact, final frame rendering is exactly the same as Interactive Rendering, only with scene updates disabled. The outputs of IR and final rendering are not visually different, as they are both capable of producing exactly the same effects, support the same features, and even use the same GI solvers. IR, just like regular VFB rendering, will react to exposure controls and other post-processing effects in real-time. The only differences are:


    When rendering, IR gives immediate response, while regular rendering is faster in the long run. This means that Interactive Rendering should not be used to produce finals.
    IR internally uses slightly different render settings than regular rendering (for example lowered GI vs. AA balance). This is done to achieve best responsiveness, and does not affect the image quality or appearance in any way.
    By default, IR does not use all CPU threads, so it is slightly slower in the long run than regular rendering. This is to allow for viewport navigation and other background activities to run smoother. This can be changed under system tab > system settings.

Just accepted the fact - less glossy bounces. Didn't bother to ask "how many", never thought of it as a bug... now, clarification is a must ;)

[Nejc Kilar]

Hey burnin, thanks for chiming in.

I can't really make it out from the screenshot you provided if we are having the same problem - it kind of looks like we do but I'm not really sure. Do you think you could attach another example?

In my attached example you can kind of see that the chair on the left side of the VFB has smooth and round legs. The one on the right however has a distinctive reflection break up (and a highlight too) that makes it look like the legs are more rectangular rather than round. The same could be said for the top of the chair.

That to me makes it look like a phong issue but if I disable / delete the phong tag then it looks different than what the IPR produces so I'm just not sure.

Hopefully you can provide another example so the devs can have a better idea what we are dealing with :)

[burnin]

Tests show no issue with the Phong Tag (see image attached).

[Nejc Kilar]

Tests show no issue with the Phong Tag (see image attached).

Thanks for testing! :)

This error / difference occurs only when dealing with certain objects - like the one I've sent to the devs - where the topology is ... not as cool as it could be.

I am -guessing- it perhaps has something to do with the phong tag because the final render renders it OK while the IPR renders it differently.

That said, if I delete or disable the phong tag the result is different than what I get in the screenshot attached in the OP. It is similar in the way that it looks faceted instead of round but its different nonetheless.