God's Ray-jet/rocket engine tutorial

[GateGirl86]

Like many of us who are deeply immersed in our fandom's that require us to spend countless hours building our ships; we often tend to go over board when creating those little tubes at the back to drive those ships.

You might have found that by simply slapping a disc in the end of your engine, didn't quite work out for you and so now I will show you how to avoid that big cone of light.

Once you've created your engine and placed it on your ship, (I'm doing it separately here), you need to measure the dimensions of diameter and length.

measure-1.jpg (652.47 KiB) Viewed 1770 times

measure-2.jpg (631.47 KiB) Viewed 1770 times

[GateGirl86]

Once that is done, we'll create our jam tin that will become your emitter.

I've made this just slightly smaller than my exhaust opening, at 2.2m diameter and 0.9 metres long.

cylinder 1.jpg (587.35 KiB) Viewed 1769 times

After creating the cylinder, I've group the front face, then moved it back 0.8m

cylinder 2.jpg (562.7 KiB) Viewed 1769 times

Finally adding my emitter colour and naming it.

cylinder 3.jpg (690.17 KiB) Viewed 1769 times

[GateGirl86]

Now we need to place the cylinder in our engine and finally test it.

cylinder move.jpg (594.83 KiB) Viewed 1769 times

And the test. You can clearly see my settings here.

Gods ray test.jpg (518.8 KiB) Viewed 1769 times

Happy emitting!

[Alienizer]

whoa! THANK YOU so so much for this

[Support]

You beat me at it Al, I was just about to say the same!

Thank you GateGirl, you're awesome

[Alienizer]

You beat me at it Al, I was just about to say the same!

[GateGirl86]

You're both welcome, it was a pleasure to do and something (among other tutorials) I have been wanting to do since Micheal's last upgrade

[Support]

You are so sweet. Your hubby is a lucky man to have you

[GateGirl86]

You are so sweet. Your hubby is a lucky man to have you

Now what do I say to that? But thank you Michael. I think though for what he has to put up with, I guess I'm as lucky as he is.

[Support]

As long as the feeling is mutual and that there are no negative thoughts, that makes it perfect for the both of you because you both have to put up with each other's Love, and that's ought to be a beautiful feeling.

[Okwa]

Hello,
I am new to the forum and wanted to say hello with this small picture. I wanted to use the Gategirls tutorial for both spaceship models. But on the blue freighter on the left, the drive nozzles widen from the inside to the outside. No matter what I did, when I used the method from the tutorial, there was always strong scattering of the god rays. Even more so than can be seen here in this picture. I made a virtue out of necessity. For the right-hand ship I used the method from the tutorial, for the left-hand ship I simply defined the rear end of the nozzles as the source of the god rays.
All the settings of the god rays are otherwise absolutely identical on both ships. The difference therefore arises solely from the differently shaped nozzle models and the different method of creating the god rays.
This way, you and I can compare the differences that arise from details such as model design, type of light source, and so on.

[Support]

Hello Okwa and welcome aboard

What I would do is remove all emitters that you used for the God's ray and make the back burner plate the emitter with God's ray. Assuming the back burner is flat and pointing in the direction of the exhaust flow. In the Emitter setting, change the angle of distribution to a very low angle so that the beam can be made more laser like than dispersed in all directions. That's what I do and it works.

[GateGirl86]

As long as the feeling is mutual and that there are no negative thoughts, that makes it perfect for the both of you because you both have to put up with each other's Love, and that's ought to be a beautiful feeling.

Ah well, negative thoughts, hmmm, yes there is one. Charlie loves his leaf blower, especially on Sunday mornings. I hate that bloody thing! Otherwise its all good.

Okwa, as I told you on DA, that is simply brilliant. You did a great job and as Michael said, there are a number of way around that and the method he spoke of works every time. It's all a matter of what you want to change, even if it means a little modification. The best thing about it, is that the changes will be seen quickly and you can always revert to how it was. I often save the SKP model with a 'render' tag, separate from the original model.

[Support]

Ah well, negative thoughts, hmmm, yes there is one. Charlie loves his leaf blower, especially on Sunday mornings. I hate that bloody thing! Otherwise its all good.

I hate these bloody things too, my neighbor uses it in winter too to blow the snow off his huge driveway!!!, takes him all day and it drives me NUTS!

[GateGirl86]

Ah well, negative thoughts, hmmm, yes there is one. Charlie loves his leaf blower, especially on Sunday mornings. I hate that bloody thing! Otherwise its all good.

I hate these bloody things too, my neighbor uses it in winter too to blow the snow off his huge driveway!!!, takes him all day and it drives me NUTS!

Thank god we don't have snow here. Well not at our place, close but no snowman. I would shoot the bloke honestly, that is insane!

[Support]

I would shoot the bloke honestly, that is insane!

I LOVE how straight forward you are, and comical at the same time. I'm laughing so much right now I have tears

[GateGirl86]

This is an example whereby the exhaust emitter exit isn't as straight forward and you do want people to see some detail. What I did with this was dial the settings right down, way down and then let the rendering run for a few hours to sort it out. When first turned on, the God's Ray was all over the place, but I think it was about 3 hours and this is the result. It was also one of the first models I did using the GR

City class Corvette-new.png (4.05 MiB) Viewed 1730 times

My mother lived around the corner from Paul Hogan's place, maybe his directness is in the water!

[Okwa]

Hello Okwa and welcome aboard

What I would do is remove all emitters that you used for the God's ray and make the back burner plate the emitter with God's ray. Assuming the back burner is flat and pointing in the direction of the exhaust flow. In the Emitter setting, change the angle of distribution to a very low angle so that the beam can be made more laser like than dispersed in all directions. That's what I do and it works.

Many thanks for the warm welcome.

This is exactly the method I used on the blue freighter. I made the back burner plate the emitter for the god ray. And the angle as small as possible. You can see the result in this picture.
I think the strange result comes from two things. On the one hand, the engine nozzles are funnel-shaped, widening outwards. This in itself causes a widening of the light beams, I think. On the other hand, I have made the inside of the engine nozzles without reflection/shine, but I have given the outer skin some reflection. And the outer skin protrudes a bit into the engine nozzles. So the slight reflection of the outer skin causes further scattering, I guess. Unfortunately I have already deleted the scene. If I have time, I will "reconstruct" it and play around with the settings.

[Okwa]

This is an example whereby the exhaust emitter exit isn't as straight forward and you do want people to see some detail. What I did with this was dial the settings right down, way down and then let the rendering run for a few hours to sort it out. When first turned on, the God's Ray was all over the place, but I think it was about 3 hours and this is the result. It was also one of the first models I did using the GR

3 hours? Okay, that's different, of course. I let it render for 15 minutes. So maybe it's really not long enough.

[Support]

3 hours? Okay, that's different, of course. I let it render for 15 minutes. So maybe it's really not long enough.

That's because she has a super slow and outdated laptop
If you render for 100 samples or more, that's usually enough and 300 is definitely enough.

The God's ray are not affected by reflection nor do they bounce off surfaces. They come directly from the emitter or there is no ray. To start with, set the spread and density to very low and range to very high then adjust.

[Okwa]

If you render for 100 samples or more, that's usually enough and 300 is definitely enough.

The God's ray are not affected by reflection nor do they bounce off surfaces. They come directly from the emitter or there is no ray. To start with, set the spread and density to very low and range to very high then adjust.

If I remember correctly, I stopped at 150 samples.

Thanks for the explanation, good to know. I thought there were also reflections with god rays.

I don't want to name any of your competitors. But despite having a good PC, I always had to render for at least 2-3 hours with another rendering programme for Sketchup to get any result at all. So it could also be the programme and not a poor little laptop.

[Support]

Raylectron is not supposed to stop at 150 samples because it's an incremental render and will render forever, until you stop it.

The reason it may take several hours to render, even with your other render is because of problems with the model geometry and/or the settings used on the materials. When all done and set properly, Raylectron should render fairly fast, like from a minute to 15 minutes. Unless the scene has a lot of artificial lights and glass, then it could take longer. In any case, when it's at 150 samples, it's pretty much done rendering and letting it render more may not give you any visible changes to the human eye.

The God's ray will show on reflective surfaces, but the ray will not bounce off any surfaces, so you can't make a 45-degree plate to redirect the ray for example. The reason for this is because the God's ray are not exhaust gas, they are light traveling in a smoke like atmosphere. You can use that to simulate exhaust gas but keep in mind that it's not gas.

[Support]

When I mean slow computer, I don't really mean speed (I used the wrong words), I mean parallel processing abilities. GateGirl's laptop has only 2 cores (4 threads) running at 2.7ghz. I have 8 cores (16 threads) running at 4.7ghz (in turbo mode) so it's a big difference in speed. Laptop memory speed is also much slower than that of a PC

[Okwa]

Raylectron is not supposed to stop at 150 samples because it's an incremental render and will render forever, until you stop it.

The reason it may take several hours to render, even with your other render is because of problems with the model geometry and/or the settings used on the materials. When all done and set properly, Raylectron should render fairly fast, like from a minute to 15 minutes. Unless the scene has a lot of artificial lights and glass, then it could take longer. In any case, when it's at 150 samples, it's pretty much done rendering and letting it render more may not give you any visible changes to the human eye.

The God's ray will show on reflective surfaces, but the ray will not bounce off any surfaces, so you can't make a 45-degree plate to redirect the ray for example. The reason for this is because the God's ray are not exhaust gas, they are light traveling in a smoke like atmosphere. You can use that to simulate exhaust gas but keep in mind that it's not gas.

Thank you for the explanations, very interesting.
15 minutes on average? Impressive. Unfortunately, I am now used to worse rendering times. That's the main reason I've cut down on publishing rendered images over the last 2-3 years. I don't have enough time to allow my PC to spend one, two or even three hours rendering an image.

When I mean slow computer, I don't really mean speed (I used the wrong words), I mean parallel processing abilities. GateGirl's laptop has only 2 cores (4 threads) running at 2.7ghz. I have 8 cores (16 threads) running at 4.7ghz (in turbo mode) so it's a big difference in speed. Laptop memory speed is also much slower than that of a PC

Sorry, the "poor little laptop" thing was a little bit of a joke. As some people, including GateGirl I think, can tell you, I tend to be sarcastic from time to time and, more importantly, I forget that you can't see it in written comments. It's a weakness of mine.

[Support]