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Five Minute Tip – Simple Gobal Illumination in Cinema 4D


Hi again, in this five minute tip, we’re going to
be taking a look at some simple Global Illumination let’s say you have a few objects like these
and you wanted to light them really quickly. Maybe to show off
for a presentation or you just wanted to render
them on a nice simple colored background. How would
you go about doing that? one of the techniques I’ve used
for a long time is a simple global illumination formula that uh… comprises of a sky dome, a floor, a very simple material, and a few carefully chosen settings. before we dive into that I’d like to explain one option that we’re
going to want to turn off before doing this and that option is the
“auto light” option there’s an automatic light in
Cinema 4D that’s on by default if we do a render we can see that it’s lighted the exact same way
it looked in the viewpoint we can go to the default light, and change
it; and it controls what we see in the render. We’re gonna turn this off because it’s going
to influence our results and I want to keep those pure. so we just goo to Options>in the render settings and turn off the default light the next step is to get a sky and a
floor going. So I’m just going to create a floor object and a sky object if we hit the render button now, the
results going to be very unimpressive we just get a dim sky with a
silhouette of our scene I have a material that I’ve created
and it’s pure white one hundred percent white. You can apply this material to the floor and to the sky then render again and our results are still the same this is because we’ve turned off all the
lighting and we haven’t replaced it yet so let’s go ahead and replace it
with some indirect lighting you can go to the effect part of the
render settings this might be different if you’re using an older version and we just choose Global Illumination right away, if we do a render we can see
our results are pretty different we get a pre-pass some funny-looking dots these are actually
sample points where Cinema 4D is testing the indirect light and it’s actually going to do
this for a while its just goint to churn away here, and
the results it’s going to create are going to be pretty nice… but we don’t have time for that so I’m gonna change the record
density to “low” (the low preset) I’m going to change the samples to “low” (the low preset) and I’m going to make sure in the general
tab; the “diffuse depth” is set to “1” with these simple tweaks we can render again and you can see that the pre-pass
is much more coarse but it finishes much more quickly and now we have something that looks
like uh… flat render and it could be a little more useful in
presenting the scene now it’s easy to call this “done” because our materials don’t
have much diversity so let’s and some materials to the scene and see what happens I’m going to add that sort of
clay material to the engine and I’m going to add this yellowish
material to the sphere then I’m going to add this orange
material to the cube and cylinder so if I do another render, you can see that our materials are going to be applied properly but something pretty crucial is
missing from them and that’s “specular highlights” there’s no shine on any of
these materials and that makes perfect snese because
we got rid of all the lights the only illumination the scene is getting is from every single direction one color, white light all of the shading we’re seeing is
created by occlusion and shadowing so we can tweak this by adding a light to the scene fairly straightforward… so I’m going to change to my shaded view were I can see my lighting and if I place this light up here we can see a specular highlight on the spehere and on the cylinder little bit on the cube as well, we can try to do another render… it works but everything’s washed out
because there’s a large amount of light being produced because we added a light! we can tweak this by clicking the light, going to the “General” tab and turning off “Diffuse”
and “G.I. Illumination” that leaves us with just the specular
information from this light we can then adjust that to our liking by adjusting the intensity slider we can do another render and the result we’re going to get will be much more pleasing because we have these
subtle shines on certain parts of the objects the scene is almost complete, but there’s still a few gaps in the G.I. the cube kind of looks like it’s floating
in space and some of the shadowing isn’t as tight as it should be. we can change that either by adjusting
the G.I. settings which in my experience, sends your render times through the roof
(for a simple scene like this) or… we can add an
“Ambient Occlusion” effect so if we had the
Ambient Occlusion effect I usually like to start with
Minimum samples: 8 Maximum samples: 32 If we do another render now, we can see that the render pass is
going to take a bit longer… (significantly longer) but our pre-pass was still
nice and quick and we’re getting some really
nice shadowing right where the components get really
tight in the scene and the objects bump up
against each other. This simple set of steps is something
I’ve been using for a very long time to create renders that really isolate
the subject on a white background while providing an even and fair amount of
lighting to all of the scene. So, that’s it for the tip!
I hope you enjoyed it, and until next time…
see ya!

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