Rendering an Eclipse?
DaWaterRat
Posts: 2,882
Okay, my quick test in iray of paintstakingly lining up the TerraLuna3 and the sun from an HDRI resulted in learning that *that* method won't work (primarily because the sky stays bright - and yes, I turned off the emissive on the moon) so ...
Other than getting an Eclipse HDRI, does anyone have any suggestions? Right now, I'm leaning towards a night sky HDRI with an emissive flattened sphere (so a disc) as the sun, and then positioning the moon in front, but if someone has a better idea, I'm quite open to it.
Admittedly, this is more for curiosity than anything else, but it's the sort of thing that could come in handy.
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You could also try using a night HDRI and a torus with a very small minor diameter compared to the major diameter and then use it to surround a black sphere or maybe place a black disc in back of it to prevent the background image showing through.
You could try to overlapping circles & render in 2 passes: one only having the overlaping circles rendered with bloom turned on.
when I read this I thought about how I would do this scene and I think I would try placing my moon prop in front of a god rays prop https://www.daz3d.com/epic-props-godrays-volumetric-light-for-iray and ajust accordingly you can see some of the effects in the promos
you might find you can scale the light ray prop enough get the moon prop to block the light source settings thats incuded in the godrays prop to help you set up it up. This I think would allow the God rays to surround your moons prop like real sun rays realisticly, I would also pair it up with just a pre evening sky back ground. as this not a night sky setting actually. I think I would give that godrays prop a try . I believe you could do it with out having to use post work this way
interesting... using Carrara
used a tourus and sphere primitive using glows and light effects.
A while back when I made my first steps in Iray I made this render. The trick with it is that I used a simple sphere made it emissive in bright sunny colour and placed it in front of a simple plane (no coloring just Iray basic). So I think one could try a similar setting with a second sphere a bit smaller and non emissive in front of the first.
The blurr outs on the sun are postwork here and there is DOF and vignetting active just to make the information complete
Don't look at it if you don't have the special glasses. Instead, can poke a hole in a shoebox.
(EDIT: created a crescent shaped emissive object to cast the light from the front, and modeled a box with a hole in one side. Carrara render).
(EDIT 2: NASA has instructions for making an even fancier observation device with ordinary materials https://www.jpl.nasa.gov/edu/learn/project/how-to-make-a-pinhole-camera/)
so the pinhole in Carrara actually worked like a physically based one projecting the light on the back in the correct shape, interesting
I show the scene setup in the Carrara forum. I'm not sure a point light like a default spotlight would have gotten as good results through the pinhole. I think it worked because I modeled a vertex crescent and then used anything glows set to facets. I also used a primitive cylinder as a moon to block the crescent sun, just in case. In Studio, I believe similar results could be had by making the crescent an emissive, but I haven't tried it.
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Of course a point light shouldn't work, the eclipse effect works in real life because opticaly from the surface of Earth the moon and sun are almost the same size (it varries a bit based on where earth and moon are in their respective orbits
Cool information. Thanks.
Sadly, the moon is (very) slowly drifting away. https://moon.nasa.gov/about.cfm
So... let's see. At 1 inch per year it will take the moon 39,370 years to put 1km of extra space between it and the earth. I'm not worried about it running away any time soon.
Guess I am more optimistic about that anti-aging research.
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Right now, NASA scientists are discussing Monday's solar eclipse on C-Span. Maybe at c-cpan.org if outside the US?
Interestingly, that we have eclipses is about a 100 million year window humanity happens to exist in; in another 40-50 million years the moon won't occlude the sun fully.
A fun thought is that if we ever discover FTL and aliens, eclipses might be a tourism industry, since it's unlikely other inhabited worlds will have them.
"turn into" :-) I take it you're not living anywhere near totality?
I went with a kind of combo, based on what I already had in my runtime.
For the moment, it's in the PC inspiration thread for this week, though I'll post it here and on my DA account when the contest is up. (The renders are supposed to be new for the challenge, so I don't like to post them elsewhere until the contest is over so that there's little doubt that they're original.)
I heard as a child one day the moon will fall into the ocean right on top of San Francisco. The other theory was that it would break apart and turn into a set of rings like Saturn has but a much more dangerous set of rings as the rocks would be mostly bigger than asteroids. It was a real science book I checked out of the library that said that and one that was written for adults after you stop laughing.
The aliens that brought the moon here will take it back away I'm quite sure!