Electron Tube Project

[spreadcore]

This is my attempt at modeling & rendering the cathode ray tube J.J. Thompson used to conduct experiments that would prove the existence of electrons. Mainly to learn the settings to use in rendering.

Next I'm looking to add a "Electron beam" in the tube, My first attempt was just using a long cylinder with a emitter to give it a glow placed inside. But that just looked like a cylinder with a glow. Not a Plasma like beam, What would be a better way?

JJ-Thomson-Cathode-Ray-Tube-01.jpg (733.19 KiB) Viewed 4565 times

[Fletch]

I'm not very good with this type of scene, but can say that likely will need to use Easy 10 render setting.

These 2 scenes may help:

Download this scene:
Subject: Neon Tube Sign Light

Look for all the downloadable scenes in this thread:
Subject: Optics

[spreadcore]

I'm not very good with this type of scene, but can say that likely will need to use Easy 10 render setting.

These 2 scenes may help:

Download this scene:
Subject: Neon Tube Sign Light

Note: I'm not able to assess this link, It says "You are not authorised to read this forum."

Look for all the downloadable scenes in this thread:
Subject: Optics

Thank you I'll take a look at this link.

[Fletch]

Oh, my apologies, that forum is for licensed pro users only.

[spreadcore]

Okay I'm getting closer, After reading the Optic's thread (which appears to be just light on surfaces) and watching the video Volumetric Lighting Tutorial (I also read a Tut. from Lightup about making a fake volume light, which I thought was interesting )

I made a little test setup, before I try putting it in my E.tube model. I have two light sources, a point light and a spot light inside a cylinder that uses the volumetric template on it. I'm still playing with the settings for the lights and background, But this is pretty close.

I'm wondering if there is a way to make the spot light "beam" light rays look more parallel instead of cone shaped.
Update: I believe solved this.

light beam test.jpg (46 KiB) Viewed 4534 times

[spreadcore]

Question: When I attempted to make the light set I showed above into my model, I found it didn't work.
Here is a example of whats happening. The cylinder on the left is 5" in Dia. and has the volumetric template set to it and a point light inside. The cylinder on the right is the same except it is 2" in Dia. all setting are the same except for size.

When rendered, the smaller cylinder disappears There does seem to be light emitting from that area, you can see it shining on nearby object if there is one.But the cylinder is gone Render setting was Low

So is there some kind of Minimum size for object and/or lights to use the volumetric settings on or is there some setting that needs adjusting on lights or volumetric that needs adjusting.?

example light prob.jpg (207.76 KiB) Viewed 4525 times

[Fletch]

these volumetrics materials are basically "faking" volumetric lighting. They can not be rendered with Easy 09 or 10. Only Easy 1-7.

That said, since it was developed specifically to get a quick look, and not to be physically accurate you are going to find ways to "break" it.

Are you trying to make something that is a working (based upon the physics of light) model or is it supposed to be something that simply "looks cool" type of artwork? If you want better input you will need to share the models you are testing with here on the forum. Otherwise it's all wild guesses from our side.

With hobby version you will not be able to use the DEEP material editor, and all additional libraries of SSS materials that are available to pro users... so naturally you will be limited in what you can achieve due to hobby limitations. This appears to be an extremely technical rendering and would likely require access to the deep material editor. But, as I stated earlier. This type of rendering is not my forte. I just do arch viz and basic props/product shots.

Do you have a photo example of what "look" you are going for?

[Fletch]

from a video I saw online, I created this. I created a .png image plane and set it to be an emitter. The texture I created in photoshop. It's a start.
Need Deep Material editor in pro version to tweak the cathode ray transparency material.

[spreadcore]

Are you trying to make something that is a working (based upon the physics of light) model or is it supposed to be something that simply "looks cool" type of artwork?

Just mainly for the look, Given that it appears to be the model size that breaks it, I figure I'll just increase the model size slightly. That should solve the problem. I made a quick mock up at a larger size and it worked okay.


I was just checking to see if there was something I was overlooking in the settings etc.

Ar one point I did have a .png image in it. With the "rays" on it which looked alright but only from certain direction . That's what made me start thing about rendering them instead so I could rotate the model.

Thank You for the time.

Do you have a photo example of what "look" you are going for?

Here's some basic examples

cath-ray-plasma.jpg (131.44 KiB) Viewed 4467 times

[spreadcore]

Okay, resizing the model seems to have worked. The lights are working properly as far as I can tell.

I just need to reduce the intensity of the point light on the leftend (it's too bright)
and I need to see if I can increase the "Density?" of the spot light on the right (so it looks more like the left) and make it a little narrower, That should about have it.

Note: this render was done with Easy 4 medium

JJ Thompson Cathode Ray Tube-0.jpg (196.33 KiB) Viewed 4405 times