3D Lights Neon glow how to do that?

[Peac3]

I a strucked with what looks like a common obstacle but can't find any solutions on google yet.

I want to create in 3D a neon shape light, a tube that generates a glow by reflection on materials. Or a linear light source.. a neon.

Now i figured out i have to configure a self illuminating material but yet it's illuminating but not spreading any light to reflect. I read i could use a spotlight to create the light.. but a spotlight or point light won't do the linear type of glow i want to create.

The neon is inside the box in the middle of course.. there is no bottom to that box i don't know how to call this in english, in french is a " Cache néon"

Is there any quick trick to learn how to generate light out of that cylinder to reflect on the box sides and wall ?

Tx

[Peac3]

i have no success with the spot light so far.. the diffusion is just not right for the job, it's a spotlight..

Maybe ill have to put a side on the back of the box.. to prevent the light from passing between the wall and the box.. strange render situation.

[Peac3]

ohhh god..

It's not possible to do has i read there:

http://forums.autodesk.com/t5/Autodesk-Inventor/how-to-draw-a-glowing-illuminated-neon-tube-lamp/td-...

I will have to use spot or omni.. it 's going to take forever..  ill have to work for free on that job that's for sure.

Please tell me i am wrong and there is a nice neon light tool inside 2013.. i am not dreaming, 95% of buildings lights are neon it sould be somewere in Acad 2013 i am sure of it.

[Peac3]

i had some kind of success after 25 minutes of my diner time. I used like 20 spots close to each others like a strip of LED lights and with some angle on the wall.. i can simulate the neon glow. I have some light into the lens.. maybe in adjusting the reflection of these lights to something more light.

Render time was not that bad even with 20 lights, they don't cast shadow either to save some cpu time.

Still if there is another easier technique i would be glad to know.

[dbroad]

Create a 3d shape (here a cylinder 4' long).  Add a luminous material (from the autodesk library).  Add a point light and use the soft shadow.  Set the shape of the shadow to be rectangular and give it the dimensions (1" by 48").

[Peac3]

Ok i have a few questions.. First is about the Luminous material.. i am not sure how to find such thing..

I could create a new generic material, then it's possible to enable self illumination, i will get a white tube like you have on your picture but with no ray of lights emiting out of it.

Where do i put the point light? inside the tube? 

In the point light properties : Render Shadows Details, type : Then i have Soft (Shadow map) and Soft (Sampled) and sharp. Must be Soft Shadow map ?

To set the shape of the shadow to rectangular.. i really don't know where to do that.

[dbroad · Accepted solution]

See video

http://www.screencast.com/t/gHHDUvtWj

It's probably not best to put the light inside the solid.  Rather put it just below.  You can also use the linear light shape rather than the rectangle.

[Peac3]

wow! Tx for this video dbroad, really nice!

I tried and it's working, the glow i get is right like it should be. It's a great achivement, actually i don,t even need to draw the glass tube at all

Still i have a situation here, my rectangle light is inside a box with 5 sides, and no bottom.. but the light pass trough the box has you can see, looks like some kind of computing error.

I don't find any solutions yet to correct this situation, like if the solid isn't blocking the light from passing trought.

[Peac3]

After some time trying.. i didn't find any solutions. I tried removing all reflectivity from materials, the light casts no shadows.

Maybe it's because i am working on Autocad 2008 right now, otherwise i did the 3D in 2013. Maybe 2008 don't have the light reflection instructions to do the right calculation... Mental Ray ?

When i turn off my solid acting has a box, the light is right and point to the floor. When the solid is on.. i get light over the top.

What could be wrong?

[dbroad]

Using the OOTB materials will help. Your first image after my video post looks like all the materials are glass or glassy.  Way too much specular reflectivity.  Materials also have opacity settings.  If you don't want the light to shine through them, increase the opacity.  The built-in materials from the library work well.  Start with them and change the colors.

I'm on 2014 so can't comment on 2008.  Glad you solved your main issue.  The only reason to draw the light bulb is if you want to see it.  If its behind a cove, its superfluous.