Just completed first projects in C4D

[Simon Wicker]

you should set up a New.c4d with your main project frame rate already set (i use 25fps for my pal tv work) and then in 10.5 you need to save some render settings for your most used sizes/frame rates.

that way you don't need to worry about always setting things up how you would like them.

in R11 this is improved in that there are real render settings that match most comp apps (so you have a widescreen Pal DV setting that auto sets your render to 1024x576 @ 25fps, etc).

to get the floor shadows working you need to make a pure white material (colour 255, 255, 255), apply that to your floor, apply a compositing tag to your floor and then turn on compositing background.

a version of this technique is enclosed.

cheers, simon w.

[Fede]

Hi Simon,

Thanks for the reply and files.

What I landed up doing is opening up C4D, changing the frame rate in the preferences and setting up my render settings and then saved over the template.c4d file in my programmes folder, now i have those setting every time I open it up.

Thanks for the file I'll look into it.

The way I thought it would work is that the actual floor would disappear leaving shadows behind. How would your work flow then work when compositing this image?

[azmin]

If using shadowcatcher, the floor will disappear leaving only shadows. You'll comp it as per usual..on top of another image.

I haven't tried the all white floor technique though.

[Fede]

Hi,

When i render the file attached by Simon I still get the floor? am I doing something wrong?

I also wanted to ask about camera settings, in MAX i could specify that the camera be 35mm or 50mm etc, is there such a thing in Cinema 4D?

Thanks guys

[AAAron]

The way I thought it would work is that the actual floor would disappear leaving shadows behind. How would your work flow then work when compositing this image?

Render out a pass with the white floor and set it to multiply in the comp app, that would leave only the shadow.

[Jorge Arango]

Hi,

When i render the file attached by Simon I still get the floor? am I doing something wrong?

I also wanted to ask about camera settings, in MAX i could specify that the camera be 35mm or 50mm etc, is there such a thing in Cinema 4D?

Thanks guys

In the object tab of the camera object, you can specify the focal length of the lens. Aperture width is the size of the focal plane, a 35 mm still camera would be 36 since the 35mm negative is 24 x 36mm, of course, you have to use the 1:1.5 ratio in Render Settings>Output>Resolution.

[Simon Wicker]

hi,

when rendering out a shadow pass you just have to either A) use the pass as a mask or B) multiply the shadow pass over the top of the background.

to get that to work you simply have to extend the floor to cover the full frame or just add in a sphere to encompass your scene so there are no black areas.

the beauty of method B is that you retain any colouration in the shadows because of GI bounce.

the drawback with all of these methods is of course that the shadows get multiplied so where the new CG shadow crosses over a shadow in the real scene the shadows are twice as dark as they should be.

however fixing that is what compositing is all about.

cheers, simon w.

[Fede]

Thanks for all the replies guys, it' much appreciated.

I found a plugin called shadow catcher which seems to do what I want it to so I'm pretty happy now. Not sure why Maxon does not incorporate this as it's already free....

I know compositing is about fixing up things, but If I can get there 90% of the way straight out of 3D I'd rather get there that way so that I don't have to waste time rendering and comping in.

Thanks for the explanation Jorge, a bit more tech than I'd like but will have to learn i guess.

[ThirdEye]

Would you mind showing us how you do that in Max please? That way we can maybe find a workaround in C4D using similar methods.

[Fede]

Hey ThirdEye,

I would just apply a material called Matte / Shadow and bob is your uncle. But I can now do this with the shadowcatcher plugin so I've got no issues :)

[51M0N]

Shadowcatcher does have it's limitations... It can't be used for catching reflections for example.
I think something more explanatory would fit here, allowing the more experienced users to share their knowledge.

I believe what Fede wants, is a simple shader used in the alpha channel of the floor, masking out everything but the shadows. This is useful when compositing a 3D object to a scene, when we just want the object and the shadows, and we don't want to render the dummy floor or the other dummy objects.

Do you know of a manual way of doing this, besides the Shadowcatcher plugin? Perhaps a similar method could be used to mask out reflections...

[Fede]

Good point 51MON, I was trying this out now with reflections and could not get it to work....

Surely this is something that everybody would want use?

[51M0N]

You can just render the whole scene and have your passes, shadow pass, reflections pass etc, that you later multiply or whatever in the compositing.
And you can create alphas for your objects using object buffer passes and compositing tags.

But you still have to render everything in the scene in C4D, and the RGBA render is just useless in this situation, only the passes are useful.
The mental ray's system allows you to just use the RGBA by masking out the stuff you don't need.

So far the only way I know you can do that, is with the shadowcatcher just for shadows. I don't know if there is a custom way to set up the alpha channel to do this manually... If we had a shader tree it could be possible I guess (that's +1 vote for xpresso driven shader tree).
Shadowcatcher does have some limitation, but I can't recall any examples at the moment. Problems with hair maybe.

[Simon Wicker]

oh, okay. you want to do it all in cinema. i see now.

as far as i know because we don't have that capability we have all simply got used to doing everything 'in post' and just taking our renders into photoshop or AE for compositing.

i would have thought that in 100% of the time doing it outside cinema would be preferable because then you avoid any resampling of the background image (as soon as you add in a texture whether that is a background or standard kind of texture then you are resampling and loosing quality of the underlying image).

cheers, simon w.

[51M0N]

You can still do everything in cinema, is you use as background the scene you want to composite into, and compositing background at the compositing tag.

What you can't do in cinema, is create alphas for the shadows and the reflections. For the shadows you can still create alphas manually, by reversing the shadow pass, but it's pretty difficult to do this for the reflections... Just masking out everything but the shadows & reflections could prove useful under certain workflows. That's probably why shadowcatcher plugin was developed in the first place...

[Francky]

Congratulation Federico! When can we see some of the new work ? :)
Also glad to hear the transition went well.

Really nifty little plugin that shadowcatcher. That's One of the big things I was freaking out of not having in C4D. Could come in really handy. Too bad it doesn't work with Vray, would have made it more complete.

[Fede]

Hey Francky,

I'm not sure I will be able to unfortunately as they were internal government projects, I'll see though what they say.

I didn't even try going with Vray yet although I have it as I thought it would add some extra headaches, not having been proficient with it from MAX any ways. Pity that shadow catcher doesn't work in that... I guess it's just ways of getting used to other ways of working.

I've just subscribed o Cineversity and I think it was a pretty smart move.

I'll see what I can do about posting, as I said, it was nothing earth shattering though.

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