Backplate Composting Question

[BigAl3D]

So when adding an object to an image using the Shadow Catcher for shadows, I'm currently using some free HDRs in the Corona Sky object for lighting which are in the equirectangular format I presume. Now, the compositing effect works great, but the image is distorted since it's using the spherical projection. This is good for lighting and reflections, but not good for the final output since it's warped and often very soft and not sharp. What's the workflow to use the HDR for lighting and reflections, but use a proper, undistorted backplate image for compositing?

--Alex

[Beanzvision]

Hi Alex, good question. ;) Please see my test scene below on how it was set up. Also note, I have not included the HDRI & backplate image as they are too large but I have put a link to them in the zip file. I hope that helps.

[BigAl3D]

Wow, that's very eye-opening! Thank you very much. This opens up my brain to lots of things. I will add one helpful tip to this. If you make a C4D native material with the backplate and add it to the Background Object, you will be able to see the backplate in the camera view for easy positioning and camera setting setup. Simply swap out the material back to Corona when rendering. Would be nice to have Corona materials be recognized to eliminate this extra step.

[Beanzvision]

Hi Alex, I'm glad to hear this is of use to you. And thanks for the tip. Out of interest, are you using S22 at all?

[BigAl3D]

I am still on r20. Probably for a while.

[lenogre]

Exactly what I was looking for today.
We need more tutorials with corona for c4d. There is a great tut about shadowcaster on the web but it's for 3dmax.

[lenogre]

I've a problem : picture for background is rendered in low res.
I've the same resolution between my picture and the output.
MAP, SAT, etc have any influence.

[Beanzvision]

What's the resolution of the image? Can you share some examples? SAT might help here, it also uses more memory than MIP. So keep that in mind.

[lenogre]

Full 3D with Corona is perfect but mixing 3D and real pictures is too complicated for me.
AR is easier and more simple for that.

[Beanzvision]

Full 3D with Corona is perfect but mixing 3D and real pictures is too complicated for me.
AR is easier and more simple for that.

Please feel free to share the scene via our private uploader so we can examine it for errors.
https://corona-renderer.com/upload

[lenogre]

Changing Focale Distance of the camera pixelates background.
Distance Focale = 36 > background is OK
If you change it, background pixelates.