OTOY Forums

alpha channel on surfaces does not work?
(constant value 0 - 255)

I want my floor excluded from my alpha channel. So the alpha channel just shows the objects on that floor. Normally I do this in lw's surface panle, advanced, alpha channel, constant value, alpha 0. The other objects will have a value of 255.

Thos doesn't work with Octane or is there another way?

Thanks!!

Also the shadow density settings...

Freddy

Nope, sorry ... Octane currently doesn't support a custom alpha value for the surfaces. Also shadow density is a feature not supported by Octane.

You are going to need to render a second pass with your floor object disabled to get an alpha channel without the floor. As you only need the alpha channel, you can use a faster rendering configuration, for example using the infochannel kernel, to get your alpha pass in only few seconds/frame.

-Juanjo

sjonsjine wrote:alpha channel on surfaces does not work?
(constant value 0 - 255)

I want my floor excluded from my alpha channel. So the alpha channel just shows the objects on that floor. Normally I do this in lw's surface panle, advanced, alpha channel, constant value, alpha 0. The other objects will have a value of 255.

Thos doesn't work with Octane or is there another way?

Thanks!!

Also the shadow density settings...

Freddy

quick respons freddy

it s not really easy in octan to change the alpha channel.

I don t know how you want to use it but, i personnaly use the ObjectID or MaterialID (info kernel) to manage the individual alphas.

It s my only way to erase some floors or backgrounds.

Interesting to see if other guys have nice quickly tips in this case

sigmamoon wrote:

sjonsjine wrote:alpha channel on surfaces does not work?
(constant value 0 - 255)

I want my floor excluded from my alpha channel. So the alpha channel just shows the objects on that floor. Normally I do this in lw's surface panle, advanced, alpha channel, constant value, alpha 0. The other objects will have a value of 255.

Thos doesn't work with Octane or is there another way?

Thanks!!

Also the shadow density settings...

Freddy

quick respons freddy

it is not really easy in octan to change the alpha channel.

I don t know how you want to use it but, i personnaly use the ObjectID or MaterialID (info kernel) to manage the individual alphas.

It s my only way to erase some floors or backgrounds.

Interesting to see if other guys have nice quickly tips in this case

Thanks Sigmamoon but how do you do that inside octane

Strange that Octane doesn't support this, such a feature is so essential if you want to have your objects in different layers, or as in my case, some objects on a floor, to make the floor brighter or if you want to tweak a certain object in After Effects, or for special fx. . . etc . . . etc

So Otoy please add this in the next build/ release?

Freddy

About shadow density :

I wanted to lighten the shadows a bit. I rendered a normal image, then I rendered a second time with all the shadows disabled and comped them in photoshop. Worked well!



- Builtdown

Builtdown wrote:About shadow density :

I wanted to lighten the shadows a bit. I rendered a normal image, then I rendered a second time with all the shadows disabled and comped them in photoshop. Worked well!



- Builtdown

shadows disabled?? where? not in lightwave shadowtype off.

Freddy

Select object > Properties > Render > Cast Shadow

Builtdown wrote:Select object > Properties > Render > Cast Shadow

OMG! Of course!!!!

Thanks!

Freddy

Then i think i ll do 3passes

ObjectID pass (inside the info kernel)
you could tweack any objects inside ur frame (colors, curves correction etc... per obects)

pass without shadow (nice idea for your purpose thnks to "Builtdown")

personnaly i ll finish with matting the surface of the floor to got the alpha shadows pass and use it over your final frame.

i think it could be great to compose with this 3 passes, and i think could be quicker to the frame "with and without shadow cast" especially if u got many objects to select to cut off cast shadow option, but deepend of your scene and complexity parenting.

My advice just calculate one time the entire frame without shadows (quick render in many cases) and only shadow maps after. "Maybe" quicker that the entire scene with shadow on.

but it s only my mental projection