Self Illuminating Objects

[Richard]

Hi guys,

long time listener first time caller.

I am working on a pinball project at the moment and Ive run into a small snag. I want the objects my pinball hits to light up and I am unsure of the best

way to achieve this effect. The objects will be made of mostly plastic type material. I have tried placing lights inside of objects but this just kills the light off. I investigated using subsurface scattering but really I want the object to light up from the inside. I had considered faking this in comp by using my ambient occlusion shadow and colouring it but I need the light effects to show up in the chrome pinball. In certain other programs I would make the pinball bouncers etc self illuminating objects thus turning them into a light source and that would sort it but I am unsure of how to go about this in houdini.

I have attached a file with an rbd ball hitting objects which cause a light to go off (this was done in chops using objid)

Im sure one of you brilliant people will be able to give me some help.

Cheers Richard

rg_self_illumination.hipnc

[old school]

If you add a light template and reference the light shader parameter to a VEX Global Illumination light shader set to Full Irradiance you can use irradiance. Then assign a constant shader to the objects that you want to emit light and set it to a very bright value.

See the attached hip file for one example set-up.

You can also use PBR to get the surfaces to glow and emit light.

glowing_tube.mov

lit_object.hip

-jeff

[Richard]

Thanks for your help Jeff

This solution works quite nicely. It should be great for the upclose stuff. I will take a look into some alternative methods for the background action as this one is a little expensive on the rendering end.

[Aearon]

another option could be to instance lights across the surface of your glowing object, using the points of your geometry or a scatter sop.

[jason_slab]

If you add a light template and reference the light shader parameter to a VEX Global Illumination light shader set to Full Irradiance you can use irradiance. Then assign a constant shader to the objects that you want to emit light and set it to a very bright value.

See the attached hip file for one example set-up.

You can also use PBR to get the surfaces to glow and emit light.

glowing_tube.mov

lit_object.hip

-jeff

hey Jeff

In your example you have the vm_gibounce param exposed on your objects, they don't seem to be doing anything for me when i adjust the bounces between 0 to 10, I'm guessing this isn't right?

jason