Shadow catcher on maxwellrender.com?
Posted: Thu Dec 16, 2010 6:58 pm
by JamesColeman
Hello all, I'm very excited about my first post, very happy to finally be walking among the Gods in this forum, but down to business:
I was perusing
http://www.maxwellrender.com and this little beauty of an image caught my eye:
(from this page;
http://www.maxwellrender.com/mw2_studio.php)
The floor (by the looks of it pPlane1) has a material applied to it called "maxwellLayeredMaterial2", and by the looks of things... it's a shadow catcher without the need to composite, as it's using Fire.
Can anyone from Next Limit throw some light on this subject? The properties of the materials perhaps? I know how holy-grail a Maxwell shadow-catcher would be...
Re: Shadow catcher on maxwellrender.com?
Posted: Thu Dec 16, 2010 7:36 pm
by brodie_geers
Very interesting scene. I'd like to know more about the "Sun Disk" as well. Is that basically a big light emitter placed some distance from the scene to provide the soft-ish shadows?
-Brodie
Re: Shadow catcher on maxwellrender.com?
Posted: Thu Dec 16, 2010 7:53 pm
by iker
brodie_geers wrote:Very interesting scene. I'd like to know more about the "Sun Disk" as well. Is that basically a big light emitter placed some distance from the scene to provide the soft-ish shadows?
-Brodie
...my guess it's a background MXI image and a white sky dome for the illumination channel
..or maybe all the channels with a mxi (... you can see the mxi in the background channel in the image)
Re: Shadow catcher on maxwellrender.com?
Posted: Thu Dec 16, 2010 7:59 pm
by Half Life
My guess: They did a final render, composited it, and pasted it into the screencap.
Best,
Jason.
Re: Shadow catcher on maxwellrender.com?
Posted: Thu Dec 16, 2010 8:13 pm
by dariolanza
Hello everybody,
This is a very good question.
In fact this is not a shadow catcher geometry, as like JamesColeman said, it then may need compositing, and Fire doesn't perform that.
The ground is a regular object, with a regular diffuse material textured with the footage picture in camera projection. This way it stays visible, while it receives light and shadows from the scene, like a regular textured object.
Then I can use Fire to set up the environment conditions (an IBL env), include more lights if needed, adjust materials in the scene, and even move objects to fit my footage needs. And all the shadows will be casted directly over the ground as a regular textured object.
The only thing I can not move is the camera, which can never be moved in a real footage integration job like this.
This way I can show that Fire can not only be used on full 3D scenes, but it is extremely helpful in real footage integration projects.
And about the Sun Disk:
Yes, this is another handy tip: Whenever you may need to include a sun into an overcast IBL environment, or when you may need independent control over the sun and the sky intensity contributions with Multilight, you can create a disk for the sun, apply an emitter material (you know the sun setting: 5777ºK and millions of watts), and place it far away from the scene (1km of beyond, take care about the relative sun diameter).
If you are using physical sky, disable the "Use Sun" checkbox to prevent the physical sky to add its extra sun), and once you render with Multilight on, you will get independent control over the intensity of the sun and the sky separately, in case you need it.
I hope you find these techniques interesting.
Greetings
Dario Lanza
Re: Shadow catcher on maxwellrender.com?
Posted: Thu Dec 16, 2010 8:45 pm
by jc4d
dariolanza wrote:
... Whenever you may need to include a sun into an overcast IBL environment, or when you may need independent control over the sun and the sky intensity contributions with Multilight, you can create a disk for the sun, apply an emitter material ...
Dario Lanza
I'm sorry to hijack this but we have been waiting for this feature (enviroment and sun independents each others in multilight slider) to come for so long and nothing, I know that now with FIRE everything is faster but multiligh is still a need for final render.
Cheers
JC
Re: Shadow catcher on maxwellrender.com?
Posted: Thu Dec 16, 2010 10:45 pm
by JamesColeman
dariolanza wrote:The ground is a regular object, with a regular diffuse material textured with the footage picture in camera projection. This way it stays visible, while it receives light and shadows from the scene, like a regular textured object.
Thanks for sharing the info Dario, I had a feeling it would be a camera projected texture, but it's still useful to see the expert's techniques, I don't think I've ever used this exact technique and I'm going to have to try. But I'm guessing with the texture applied directly to the floor it's going to give distorted reflections on reflective objects?