Hey and welcome to Makin’ season 2: Makin’
Space. In this episode, we’re looking at
taking a photo of a real nebula, and turning
it into something we can fly through.
In this series-in-a-series, I’m going to
spend the next three episodes looking at different
ways to create Nebulas in After Effects. Why
3 episodes and not just one? Well, it would
probably end up being about 2 hours long.
So in this tutorial, I’m going to take a
photo, run it through Photoshop to quickly
remove the stars, drop it into After Effects,
fill out a background, make it a 3D layer
and add some 3D effects to make it feel more
than just a background picture.
Along with being clouds of interstellar gas,
the other chief characteristic of Nebulas
is that they are hundreds of light years across.
That shot in the preview, you’d be travelling
many times the speed of light to get that
sort of shot. Fine for documentary-style FX,
but if you’re doing these effects for your
space saga, it’s worth bearing in mind.
Oh and spoil-sport alert - if you want to
hide your spaceship in a nebula, then according
to Harvard astronomer Peter Williams, the
gas and dust are so diffuse, that close up,
you would barely see them.
But what does he know. Alright, he clearly
knows loads about space, but let’s face
it - space shots look cool with nebulas.
OK, enough jabbering - let’s jump right
in.
First off we need a Nebula. Best source for
these, after Google Image search, are Nasa’s
Galleries.
This page on Nasa’s website, seems to confirm
the images are free for use for education
and informational purposes in non-profit uses.
Just make sure you credit them.
You want an image with a relatively defined
shape - that feels in focus, and ideally not
too many stars with flares.
I’m going to pick this amazing shot of the
Horsehead nebula.
And let’s now open this in Photoshop.
And now go to Select > Color Range.
And change the Select Dropdown to Highlights.
Photoshop will now pick out all the stars.
You can adjust the fuzziness if you need to.
Don’t worry over much about getting all
the star bursts - or if you want to be more
scientific - Diffraction Spikes.
And click OK.
Photoshop has now put marching-ants selections
around the brightness parts of the nebula.
Which means we can use Content-Aware Fill
to remove them.
But first, let’s expand our selections a
little.
Go to Select > Modify > Expand. And probably
about 2 pixels should be enough. This just
increases the area Photoshop will fill in.
Now making sure one of the selection tools
is selected, right-click on one of your stars,
and choose Fill.
Then content-aware fill.
You can also go to Edit > Content-Aware Fill,
but that opens up another menu and to be honest,
I’m not going to get any better results
from those advanced settings.
Once Photoshop has done its thing, click anyway
to drop the selection and hmmm.
It’s sort of worked, but not completely.
Ignore the spots in the background. We’ll
be cutting out the nebula so we don’t need
to worry about that.
Select the Spot Healing Brush.
And now just single-click on any star outline
remaining.
On clicking it turns a terrifying black for
a moment, before it then fills in.
You can click and drag to paint larger areas
too. It’s a bit of trial and error here.
And after a few minutes work. We’re done!
Now let’s cut out the background.
If you haven’t already, double-click on
the layer so that it can become transparent.
And now select the Background Eraser Tool.
You can find it in the eraser section. Click
and hold to change to it.
And use the settings in the top toolbar to
make sure it’s sized appropriately and feathered
too.
And now, you need to click just outside the
part of the image you want to keep. Photoshop
uses hues and contrasts in images to determine
what’s background and what’s not. So clicking
here then lets me really quickly cut out my
nebula - and with a nice soft edge.
And let’s switch to the Lasso selection
tool and quickly cut out the remaining space
area. Just draw through the transparent block.
To the edge, up to the top, along to the left
and down again.
Then let go and go to Edit > Cut.
Fantastic. We now have a star-less nebula
ready to drop into After Effects.
Save it as a new image - File > Export > Quick
Export to PNG is fine.
We want the original for comparisons.
And now you can close Photoshop and open After
Effects.
Create a comp and drop in both versions of
the image.
Parent the original to our photoshopped PNG
file and scale that down until we can see
everything.
Cool.
OK, so now we need to make it 3D.
Check this box to do so.
And now go to Layer > New > Null Object to
create a null layer
Hit enter and rename this Nebula NULL.
And make it 3D too.
And now parent our photoshopped layer to that.
So that Null is now the centre of everything.
I can still move stuff around, but that will
be a control point.
If I toggle the visibility of the original,
you can see there is a bank of clouds behind
the swirl.
We want to emulate that so that we get a bit
more depth.
So, create a new layer, make it comp sized
and name it Dust.
And now let’s duplicate our Nebula NULL
layer, and rename this to NULL 1.
And hopefully, you’ve seen my tutorial on
linking CC Particle World to a 3D Null.
If not, the link should be appearing right
about… now.
The video shows you how to use expressions
to translate CC Particle World’s producer
points to a Null layer.
And then save it as a preset.
Which means I can go straight ahead and add
the user preset to my dust solid.
And now go to Effect > Expressions Controls
> Slider Control
Hit enter and rename this effect Stars Amount.
Set it to 100.
And drag it above CC Particle World.
Alt-click on CC Particle World’s birth rate
and paste in the expression from the description
below.
Basically, this expression adds loads of particles
in the first frame of the comp and then sets
the birth rate to 0.
If you want to know more about it, check out
this tutorial on makin’ starfields.
Great.
Now, set the longevity to 100.
Set the producer’s radius X to 1, leave
Y for now and set Z to 1 as well.
In Physics, set the Velocity and gravity to
0.
And the type to Fractal Omni.
In Particle, set the type to Textured Faded
Disc.
And while we’re here, set the rotation speed
to 0.
Set the Birth and Death sizes to 3.8.
And drop the Max Opacity to 25%.
Making sure the Select tool is selected…
Expand the Opacity map and colour it all in.
We don’t want particles fading - we want
them onscreen from the start.
For the colours, using the eye dropper to
select a pinky grey colour.
And the transfer mode to screen.
Now, nothing has happened. That’s because
we have set our particles to have a texture,
but haven’t created one yet.
So create another solid.
Make it 500 by 500 and click OK.
And now go to Effect > Noise and Grain > Turbulent
Noise.
This is more or less identical to Fractal
Noise, but less memory intensive.
Set the type to Turbulent Basic.
Upo the Contrast to 175.
Leave everything else.
Rename this layer Tex and then drag to the
bottom of your comp and turn off.
Back in our CC Particle World.
In Particle, expand Texture.
And set the Texture Layer to our Tex.
Set the second drop down to Effects and Masks.
OK, getting there.
But it’s only pinky-grey at the front.
So, let’s expand the Extras.
And in Depth Cue, set the type to Fog and
chose a blue-grey for the colour.
Now - let’s duplicate the Particles.
By making sure it’s selected, then go to
Edit > Duplicate.
And in the new CC Particle World 2, we want
to create a more concentrated centre to the
clouds.
So, in Producer, halve the Radius X and Radius
Z.
In Physics, the Extra and Extra Angle controls
change the phase of the Fractal Omni, so to
make it all look a bit different, set these
to 1.5 and 150. Or whatever looks good to
you.
In particle, change the type to Faded Sphere.
Drop the opacity to 10%
And in Extras, check the box for Composite
with Original.
OK, we’re getting there. But still. Hmm.
Right-click on our PNG layer, and choose Precompose
> Move All attributes.
Double-click to go into the precomp and use
a couple of masks to cut off the edges.
Just use the Mask tool and draw some rough
shapes. Then hit MM to open the mask settings,
set to subtract and feather it loads.
Then repeat for the other side.
This stuff comes down to artistic interpretation
and the picture you’ve chosen.
Back in main comp, click on the Collapse Transformations
option.
Now, on our Dust layer - select all three
Effects.
Click anywhere in the effects controls panel.
Hold CTRL and tap A to select all.
Then CTRL C to copy
Click on our precomp layer and Hold CTRL and
tap V to paste.
The picture disappears.
Turn off the Dust layer
And then on our precomp’s first CC Particle
World, expand Extras and check Composite with
Original.
Cool.
Now our 3D image layer is embedded in the
particles.
And use our Null 1 layer to lower the location
of the clouds.
Maybe go back into the precomp and add an
extra mask at the bottom to hide the harsh
edge.
We’re getting there.
Let’s add some stars.
Duplicate the second CC Particle World.
Set the Radius’s each to 2.
Set the birth and death sizes to 0.05
And the opacity to 100%
Edit the Birth Rate expression - add times
20 to the end of the slider.
So we get 20 times the amount.
Umm, maybe 40.
And now, when we animate the camera…
There we go.
In the description below, you find this comp
ready to download.
But, every nebula is different, so I’ve
also included this comp…
It’s the Eagle Nebula.
Pretty much made the same way, but I’ve
split the layer into different depths.
And that’s it. A bit of artistry needed,
but the techniques outlined above do work
with different images.
Next time - I’ll be looking at ditching
the image and instead using CC Particle World
to creates it own nebula. Which is a lot easier.
So as always, thanks for watching.
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as a human being will be validated or something.
