Anyways, I rendered an image in the PhotoShop format to have access to the different layers/renders Carrara can produce, and after seeing what was produced I wanted to know how I could take advantage of them... What do others use them for, are there any tricks that can be done with them...

In seeing what Carrara could produce, I was wondering if it was a way to have it create alpha masks of objects/items in the scene or if it's possible to have it render distance masks the way Bryce does... Would be nice, using the Camera effect can be a pita, and I wouldnt mind more control over the effect postwork anyways...

Any help, advice, ideas or suggestions would be golden =)

Oh Yeah.... I'm using PhotoShop Elements 7, and I added the diffuse layer and "shut the eye" myself, but that rendered as a seperate image... Other than that, the image loads as you see it...

I find it interesting how it sets the layer blend modes automatically... Usually I just go for the squashed render, but would be good to know how to take serious advantage of these features/layers...

Hi MC, 

What you are asking about is Multi-pass Rendering. Photoshop Elements can sort of handle the various layers but what it can't do is handle different output channels – only the full version of PS will do that. 

In brief, the various layers and channels can be used to make selections or be blended with existing layers to enhance or modify lighting - even relighting a scene after it is rendered. It's a really cool ability. Everything can be changed in post including abmient occlusion, the color of the light and so much more. 

Carrara already renders out object outlines (Object Index layer) and Dispance to camera (Depth layer), but when saved into the single photoshop file, they become channels/masks, not layers. So if you need them and Elements don't work with those(I don't use Elements, so I don't know), just render them as external (not embedded) layers and then reintroduce them back from inside your Photoshop.

I use the depth channel all the tame for adding DOF in post using Photoshop Lens Blur (I don't know whether Elements has it).

I also use the separate reflections layer to adjust intensity of and/or blur reflections.

Same with glow. I don't like how carrara handles rendering glow effects, so I just render glow as a separate layer then duplicate it, blur it and get instant atmospheric glow around all the objects which had glow in the shaders.

There are many more uses. These are the ones I use almost all the time, so they are the ones which came to mind first.

Hi Mat, the problem with Photoshop for this tak is that everything you do is permanent, so you need to copy a layer before apply any effect.

I use Hitfilm for that task because everything is realtime and I can change things all the way.

Some tricks you cam performe with Passes:

Add a Ambient Light (about 5 or 15%) and render Ambient Occlusion, will give you a better depth and more faster them Sky Light itself.

You can decrease the Diffuse channel and use more AO or GI as diffuse

You can blur the shadow or decrease the amount (value) to get more clear objects

If you want to "mask" objects you cna render the Object Index layer, that will color every object in a very easy way to select them

The good thing about passes is that you can change values for every layer and make your image more clear, at same time you can apply effects to some layers and get a new image: duplicate your reflection layers, blur it a lot and add at the top of the other, you will got some glow effect very easy.

For users of Photoshop full (not like us that use Elements), there are good plugins for DOF using the Depth leayr also.

here is video that show a simple trick with SSS, without render SSS:

http://www.youtube.com/watch?v=VvobExKzMxU

WOW, thanks for all the tips and ideas!

I had no idea so much can be done using the various passes....... Definitely going to have to try to NOT embed them, I don't think the version of Elements I use can use them or handle those advanced channels and such, and I've not used a regular version of PhotoShop since version 4 =P

If anyone else want sto offer any tips, PLEASE do so, would be great to hear them "all" =)

You always can render as images also, just set to PNG or someting like that and Carrara will generate a separeted image for every passes.

I actually like it embedded in the PhotoShop file as such... But I am curious (hurt) at what I dont have access to because of my dumbed down software, LOL =P

I havent done it and don't use gimp for the most part, but I wonder if you can pull out the channels into layers in gimp then go into photoshop

I do separate PNG renders (with alpha info in them) of objects while I hide other objects.  Then I unhide and render the remaining objects.

I can then composite the PNGs together in Paint Shop Pro or whatever, or composite PNG sequences as video tracks in SONY Vegas Movie Studio.

For partial renders like yours you can also render every light in the scene, one by one and compose it too.

I have used Multi-Pass for years now, and it gives you great control over the entire scene - especially if certain systems such as mine do not like to render out pieces with more than two people and a simple background.  

 Generally, with larger scenes, I do a pass for the background, a pass for mid-ground, and a pass for foreground- added to all of the other uses this gives me greater control over the end product.

I also use it for specific lighting- a pass for specular, a pass for ambient and a diffuse, DOF, and Zdepth as well as a pass for shadows only on certain pieces such as scenes involving buildings, cars, ect.