Rendering Layers

alanthompson9187

Hi all... I have watched tutorials and they mention rendering in layers to save render times and do post work in photoshop. But how do you render layers ? I one tutorial i mention rendering the lights only, dos this mean turn off everything else in the scene and just render the lights only ? How dos that work.

I got so confused wathing one tutorial on turning things on and off i gave up, was just wonering if some one could explain how to render layers ?

Thanks.

R25S

I never done it but I would say you first render the background and ground, than you render objects and than the figures (if you have multiple figures in the pcture you render them one by one) after done that you put them together (layer by layer) in Photoshop or a similar programm and finaly adding postwork effects.

jaxprog

I render in layers frequently and you have the right idea. Build your complete scene. This will include all your lights and choosen camera position. The idea of rendering in layers is to control light. Each layer you render is some lights on and some lights off. For each light you have it can be a layer. Or you can create sets of lights.... however you want to do it. Once you have your layers you load the as a stack into Photoshop. Each layer in Photoshop now represents a light and you use the opacity to control the intensity of that light in your image. Apply some layer adjustment or filters or add-in tools such as Topaz Labs and you post work your image to something you think is wonderful and cool.

Keep in mind that what I just said.... there may be other people out there who render in layers using different techniques which I am not aware of and it gets esoteric where such methods are not likely going to be shared with anyone... at least not without something of value in exchange.

IceDragonArt

Also save your layers as .png not as .jpeg.  the .png will be transparent where there is blank space (if you want to add post work in between layers like fog or whatever then you need things to be transparent between so that it looks like its behind the character, props or whatever as well as in front of them)

Tobor

The techniques are different depending on whether you are using 3Delight or Iray. The responses will be more productive if you are explicit in the rendering engine you are using.

 

Esemwy

Generally, rendering in layers requires you to render your scene or scene subsets alternately with each light. You also need a set of masks (or PNG trnasparency) for each scene component that you wish to manipulate independently. Iray can do all these renders/masks at once using the canvases feature, while 3Delight will need to do them in separate passes, which are individually very fast. Once you have a full set of layers you composite them in photoshop or gimp with a combination of layer blend modes and opacity to determine how much from each layer is contributed to the final image. I wrote a tutorial a while back on "relighting" with this technique for Iray. When I was using 3Delight more, I used a product from Dreamlight, "Light Dome Pro - Revolution," that was fairly helpful. 

alanthompson9187

Thank you very much for taking the time to answer , I want to use Iray as the render engine, I have no idea what or how to use canvases,  I also used the Dreamlights Light Dome Pro product, But that can only be used in 3Delight as far as I am aware. Its those layer types in Lightdome Pro that i want to learn to do and re create in Iray .

Thank you very much for the links to the tutorials I will take good look at them and attempt to do something, I will let you know how it turns out, again thank you all very much.

 

Tobor

To go back to your original post, rendering separate canvase does not save render time. It may save post time in not having to re-render a scene for some reason, but for many kinds of canvases, rendering can actual be much longer than if you just create the composite scene to begin with.

Though Iray allows you to control the rendering of lights, and their contribution to the various scene elements, is this what you want to do? Or are you looking instead to render different parts of a scene, then combine them creatively in GIMP or Photoshop? If the latter, for example, you can render a person's body, then an article of clothing as a separate layer. Only the exposed parts of the clothing are shown. With your graphics program, you can then place clothing, on top of the body, and then use filters and other features to change just the clothes. The body is not altered, as it's a separately rendered layer.

For something like this, you don't really need the light path evaluations, so you can simplify that part. You work instead with the Beauty canvas, and select one or more items in a Node list. Only the nodes that are checked off will be rendered. Note that  nodes must be separate objects, not bones or other integrated parts of a main object.

alanthompson9187

Thanks again, but still getting it wrong, i tried using the canavases, and it wouldn't let me save out the seperate layers in to a folder, no idea what i'm doing wrong.

Thank you for taking the time to help.

Roman_K2

Here's my take on this. I do use "masks" in my work, but not the way Esemwy suggests; in fact I have no experience with this type of mask at all, probably to my detriment. Time to learn more stuff etc.

Ok, suppose though that there is a really big model in the background (such as Larsen's castle, which crashes my itty-bitty computer) and you've got a Genesis 3 figure in the foreground wearing, say, a suit of fur done in LAMH (Look At My Hair)... not sure exactly how all of this would go, I'm just theorizing. Your results may vary.

First thing to think about is maybe keeping resource consumption down to a minimum - in this case I might want to delete those castle components which aren't in the scene or aren't that important or aren't really used at all, for example the polygons on the back side of the building. Lots of ways to do this incl. the Geometry Editor which, to make a long story short, can remove polygons. Once you have the castle set up, in this imaginary two-layer "scene" that I'm suggesting, any render of the castle becomes the "background" and if we like we can call it a layer.

For the figure in the foreground, specifying ".TIF" in your render settings (the drop-down list of choices is next to where you write in the file name) writes the figure onto a transparent background right from the get-go. Any image editor that supports layers will load this file, and the "null" background is often represented with a gray-and-white checkerboard.

There are some benefits to "splitting the work up" this way. One key plus is that you can position the foreground figure or layer or figure-in-a-transparent-layer or whatever you want to call it, EXACTLY where you want it in the scene in EXACTLY the correct size relative to what's in the background or other layers below.

Sometimes when you go through a long render that takes all night or a couple of days (or whatever) and you step away from your work and come back with fresh eyes, you end up wishing you had altered the composition in some way. Separate layers give you a chance to tweak things a bit.

Here's a HQ render of G2F as a TIFF file, that is it appears on a transparent or null plane - the checkerboard. Nothing is there. Pretty nice clean edges though in Iray, and you can lasso them a bit and blur them half a pixel's worth if you want.

Next, the same layer superimposed on ANOTHER transparent layer, a free sample .PSD file of a palm tree that I downloaded from Turbosquid. Again, pretty nice and clean edges all around.

Roman_K2

P.S. I guess the reason I mentioned the "fur suit" is I was thinking of AM's bear which comes with a sort of separate, optional covering or "suit" made of LAMH. Has to be one of the most resource-intensive models in the DAZ store, wow.  I do like it though!

alanthompson9187

Thank you very much, i will start to do this, Again thanks very much for taking the time to explain it to me, thank you.