Daz Rendering character without background while keeping lighting intact

[LadyLilith-3D]

Basically what I'm trying to do is render a scene with just a character, omitting all other assets and keeping the lighting from the scene intact. This way I can save on huge rendering time (the scene it self if big) and just render the character in different poses. Then in post or even in Renpy, add in the character to the background I already rendered. I looked at canvases but that just renders the whole scene and let's you split up canvases in post. Any ideas?

 

[Deleted member 1121028]

Ok I think I got it, alpha make me scratch my head but this should work .
Not sure about rendering time gain tho, you will tell lol.

1) First, select your figure on the scene pane, Select>Select Children. That way we sure we got all nodes from that figure (hair, cloth, eyebrows, genetal, earring and so on).



2) Go to your Content Library pane, go to Script>Utilities>double click on "Create Advanced Iray Node Properties.dse"



3) With still your figure/children selected, go on the Parameters pane, click "ALL", then search for "iray". In "Iray handle" put any name you want (I went for 111, so remplace 111 in my exemple with what you choose) and hit enter.



4) Now on Render Settings pane / Advanced Tab : enable Canvases, click the "+" and choose "LPE" instead of "beauty".
Copy paste this in expr : E '111' .* L
Which gonna isolate our "111" Iray handle from the rest but not from light(s).



5) Last but no least, in Render Settings pane / Editor Tab, go to Alpha, set Default Alpha LPE to "custom".
Copy paste this in Custom Alpha LPE : E ([^'111'] .*)? L?
Which mean somewhat everything that is not '111' Iray handle is now Alpha.



This is the result of my exemple :

 

[Lewdpanda95]

You can specify which objects to render in a Beauty Canvas. Create a new node list and select your character and its children in it. You then have to select this node in the Canvas settings above and check the checkmark for the Alpha channel.

Is there a difference in how it is rendered with your method no_name or is it just the same thing in different way? I have no idea what a LPE canvas does.

 

[mickydoo]

I have always done it like this

For the character -
Type Beauty
Tick the alpha box
Nodes - create from selection

Then save it as .tff as opposed to a .png as the latter can leave a black mark around the edge when you combine them.

For the background -
The same as above but untick the alpha box and saving as a .png is fine.

 

[Deleted member 1121028]

Ok 1 more less drunk lmao
Simply put, Iray handle & LPE (should or Iray got problem) show 100% accuracy than anything else (nodes ID, Material ID and so on, who are kinda crap)

Iray 2014 allows the use of handles (i.e. arbitrary names) everywhere in LPEs. This means that it is possible to tease out contributions from any given object on a per-sample basis so that the result of the separation is subpixel accurate and even works with motion blur or depth of field. The added advantage is that LPE handles are more readable than integer IDs.

 

[Deleted member 1121028]

I should also stop being drunk on week end while I'm at it

 

[LadyLilith-3D]

Ok I think I got it, alpha make me scratch my head but this should work .
Not sure about rendering time gain tho, you will tell lol.

1) First, select your figure on the scene pane, Select>Select Children. That way we sure we got all nodes from that figure (hair, cloth, eyebrows, genetal, earring and so on).

View attachment 1044652

2) Go to your Content Library pane, go to Script>Utilities>double click on "Create Advanced Iray Node Properties.dse"

View attachment 1044655

3) With still your figure/children selected, go on the Parameters pane, click "ALL", then search for "iray". In "Iray handle" put any name you want (I went for 111, so remplace 111 in my exemple with what you choose) and hit enter.

View attachment 1044657

4) Now on Render Settings pane / Advanced Tab : enable Canvases, click the "+" and choose "LPE" instead of "beauty".
Copy paste this in expr : E '111' .* L
Which gonna isolate our "111" Iray handle from the rest but not from light(s).

View attachment 1044667

5) Last but no least, in Render Settings pane / Editor Tab, go to Alpha, set Default Alpha LPE to "custom".
Copy paste this in Custom Alpha LPE : E ([^'111'] .*)? L?
Which mean somewhat everything that is not '111' Iray handle is now Alpha.

View attachment 1044676

This is the result of my exemple :

View attachment 1044760

View attachment 1044726

Thanks for going into such detail about this. Going to give it a try tomorrow and see how it turns out. Thanks again!!

 

[Ashenthorn]

I don't understand the problem...
Why can't you just render the scene with the lights and character only and save as png or tiff?

 

[mickydoo]

I don't understand the problem...
Why can't you just render the scene with the lights and character only and save as png or tiff?

The light you get on the character is dependent on the environment, without it character will not match the room, and it's pretty obvious too. It bounces off walls etc and creates hues and shadows.

 

[Deleted member 1121028]

I don't understand the problem...
Why can't you just render the scene with the lights and character only and save as png or tiff?

You mean hidding everything except figure/lights? Because lights bounce all over the place over differents surface, creating contrast and shadow(s) you may want to keep.

If you mean using LPE over node list, because it's just more accurate and less clunky to use imho (not tied to 1 node list, not redo said list each time you add something, fully works in preview...). But I guess everyone got their own way tho.

 

[rocthered]

Ok I think I got it, alpha make me scratch my head but this should work .
Not sure about rendering time gain tho, you will tell lol.

1) First, select your figure on the scene pane, Select>Select Children. That way we sure we got all nodes from that figure (hair, cloth, eyebrows, genetal, earring and so on).

View attachment 1044652

2) Go to your Content Library pane, go to Script>Utilities>double click on "Create Advanced Iray Node Properties.dse"

View attachment 1044655

3) With still your figure/children selected, go on the Parameters pane, click "ALL", then search for "iray". In "Iray handle" put any name you want (I went for 111, so remplace 111 in my exemple with what you choose) and hit enter.

View attachment 1044657

4) Now on Render Settings pane / Advanced Tab : enable Canvases, click the "+" and choose "LPE" instead of "beauty".
Copy paste this in expr : E '111' .* L
Which gonna isolate our "111" Iray handle from the rest but not from light(s).

View attachment 1044667

5) Last but no least, in Render Settings pane / Editor Tab, go to Alpha, set Default Alpha LPE to "custom".
Copy paste this in Custom Alpha LPE : E ([^'111'] .*)? L?
Which mean somewhat everything that is not '111' Iray handle is now Alpha.

View attachment 1044676

This is the result of my exemple :

View attachment 1044760

View attachment 1044726

I have just registered to say thank you to you.
The canvas method did not work for my scene where a half-transparent cloth was on my figure. Your method perfectly solved my problem and saved my day!
I wonder where have you got such knowledge!

 

[Deleted member 1121028]

I have just registered to say thank you to you.
The canvas method did not work for my scene where a half-transparent cloth was on my figure. Your method perfectly solved my problem and saved my day!
I wonder where have you got such knowledge!

Now stay with us, grab a beer and enjoy your stay \o/
It's not that such knowledge tho, what's good with LPE, is that it's shared by many engines - it's the same grammar, so there is plenty of ressources.

 

[Deleted member 1121028]

>Run into Iray problem
>Google problem
>It's my own thread

 

[Rich]

Is there a difference in how it is rendered with your method no_name or is it just the same thing in different way? I have no idea what a LPE canvas does.

"LPE" stands for "Light Path Expression." Essentially, it's a fairly sophisticated way of telling iRay exactly what you want rendered on a particular canvas. I very simplistic (and probably slightly erroneous) description:

1. iRay (like most renderers) creates a scene by throwing out rays from the camera, figuring out what those rays pass through (transparent/translucent materials), what they hit (solid materials) and maybe bounce off (reflective materials). Let's ignore transparency and reflectivity.
2. When the ray hits an object, that's what that pixel on the screen is "seeing." (We'll ignore edges.) So, then, iRay has to figure out how that's lit. So it throws rays out from there toward lights, and also more-or-less randomly to find out about light bounces, emissives that aren't "lights" and all that stuff.
3. Each of those rays (light paths) is tagged with what's going on with it. Light Path Expressions allow you to say "yes, include that" or "not don't include that" in the pixel that will eventually be written out to the file.

So, with LPE's, you can do things like:

• Include only certain objects in the scene, excluding other objects. (This is what No_Name is doing.)
• Including only the contributions from certain lights. (i.e. "what does the scene look like if only lit with that light source)
• Only including indirect light paths with a certain maximum number of bounces. Or minimum number of bounces.
• Only include specular or glossy or other contributions.
• Lots, lots, lots more

I strongly suspect, but cannot prove, that things like the "Beauty" canvas and some of the other available canvases, are just shortcuts for various LPE's, since I would expect that iRay would end up using a single filtering mechanism under the hood. What the exact translations are, I can't tell you. (Although, see

You must be registered to see the links

) There was a

You must be registered to see the links

that explored this and has some links, but it also became obvious that the people there couldn't get one-to-one translations between what Daz Studio ends up providing and what the iRay docs suggested. Whether that was because Daz has done something special with iRay, or whether the docs just weren't up to date at the time I don't know.

LPE documentation for the hideously curious:

• You must be registered to see the links
• You must be registered to see the links

 

[Deleted member 1121028]

I strongly suspect, but cannot prove, that things like the "Beauty" canvas and some of the other available canvases, are just shortcuts for various LPE's, [...]

I think canvas/pass are direct raw outputs (who are very basic & common) within the engine/shader. Why would they need LPEs? Or maybe I don't understand/miss something it's possible lol.

 

[Rich]

I think canvas/pass are direct raw outputs (who are very basic & common) within the engine/shader. Why would they need LPEs? Or maybe I don't understand/miss something it's possible lol.

What I meant was that the various canvases might have been implemented, under the hood, using LPEs - that LPEs might be be the low-level way of selecting what gets rendered, and that the canvases were implemented with "precompiled sets of LPEs." I don't know that for sure, of course, but there seems to be a fair amount of overlap between them, and if I was the programmer I'd have picked one underlying mechanism, even if I made various "convenience" results available by other methods.

 

[Deleted member 1121028]

I don't think it's true imho. It also seems a bit convoluted tho if I'm honest.

That said, as you said earlier, Daz has done something special with iRay.
I think it is. If you mess with MDL bricks (don't do that, you will have to reinstall Daz), you'll see it can override even Shader Mixer.

 

[ihl86]

Hey, I saw you have a lot of knowledge and was wondering if you could help me with a similar although different problem:
I want to render a character and their shadow on whatever it falls, but I don't want to render the objects on which the shadow falls.
Is that possible?
Thanks.

 

[Deleted member 1121028]

Hey, I saw you have a lot of knowledge and was wondering if you could help me with a similar although different problem:
I want to render a character and their shadow on whatever it falls, but I don't want to render the objects on which the shadow falls.
Is that possible?
Thanks.

Not sure about knowledge part lol
Should be around the same procedure with a twist.

Open you scene

Select your figure on the scene pane, Select>Select Children then Create Advanced Iray Node Properties
In parameters put "111" (or whatever you want) as iray handle for everything

Select everything else from your scene EXCEPT your figure, Select>Select Children then Create Advanced Iray Node Properties
In parameters put "111" (or whatever you want) as iray handle for everything
In parameters Enable Iray Matte ---> "ON" for everything

Render Settings pane / Advanced Tab : enable Canvases, click the "+" and choose "LPE" instead of "beauty".
Copy paste this in expr : E '111' .* L

Render Settings pane / Editor Tab, go to Alpha, set Default Alpha LPE to "custom".
Copy paste this in Custom Alpha LPE : E ([^'111'] .*)? L?

Render Settings pane / Environment Tab : Draw Dome/Draw ground = "OFF"

Should render figure+shadows of your scene. You can of course choose what catch shadows or not on your scene, I did it for the full scene but it's up to you. Here test result, I put a white background to see better:




I never needed that kind of layers, so I don't know if you will run into some complications, it's possible tho.

 

[RVNSN]

Thank you for this thread, I appreciate idiot's guides. Saved this thread awhile ago and glad someone made a comment, because I never tried it and forgot about it. I think I know the answer to this, but with mickydoo's comment about using tiff instead of png, will that also happen with LPE? I've been doing spot renders and saving out as png, and I have to erase the edges of the spot renders because it does that.

Edit: also, with the method to render and catch shadows, does it render shadows from the non-rendered items?