Video projection

[babumbol]

Hi there!
Recently I tried some Video projection style scene. Normally you would use a spotlight and apply a texture to it. As this is not possible in Corona, as far as I know, I tried different solutions.

Frist one: Light Material with 100% Directionality. This actually doesn't work very well. The resulting image is extremely blurred. You can size up the Light Material Plane to sharpen the image. But there are limits to this approach, when doing interior stuff.

Second approach: Plane with a Texture in the Refraction channel. And a light source behind it. Works like a real world projector, but the light source must be very small, to get a sharp result. This results in ridiculous light like 999999 and Exposure up to +20. That's ruining every scenes light balance.

I couldn't figure out another, practial solution. So maybe someone over here got an idea?

PS: Attached you can find a sample image. Left hand-made projector, right side plane with Light Material.

[davetwo]

You can just use a native C4D light, no?

[babumbol]

Whenever I tried it, Corona crashed C4D.

[Beanzvision]

It definitely works with both C4d square spot and C4D material (colour image in the alpha slot). ;)

[babumbol]

Thanks, it worked like you described.

[johnnyswedish]

Hi babumbol,

I am working on something similar and used the same technique. I did have problems as my projection was 16:9 instead of square. I made the square light fit the width of the projection canvas and made a mask object in front with a 16:9 hole and added a corona comp tag to hide it. Have a good weekend :-) John

PS: I have not turned down the ceiling lights yet 😎

[luis.lab]

It definitely works with both C4d square spot and C4D material (colour image in the alpha slot). ;)

Hello,
Im having the same problem testing a video projection however did not understand this technic, in my test comes out in black and white...
should I make 3 lights/masks for red, green, blue?
Thank you guys

[Beanzvision]

You shouldn't need to create 3 spots (can be done but not needed). I have attached a screen file for you, enjoy! :)

[luis.lab]

Works perfectly now!
thank you so much :)

[Beanzvision]

You're most welcome! ;)

[TomH]

Any ideas on how to make the projection visible with Interactive Render?

[Beanzvision]

Any ideas on how to make the projection visible with Interactive Render?

It's not possible with Corona. You could try Cinema's interactive render region or the plug-in Magic Preview. I haven't tried either so I can't say it that will work or not.

[TomH]

I didn't think to use the Interactive Render Region (I only recently started with Corona). I also tried NitroMan's MagicPreview, which still works in R20 but is much slower to render than the IRR.

As an adjunct to this, should the native C4d lights Project Include/Exclude work in Corona? It has no effect for me.

Thanks