Isotropix Forums

About light path expressions

So you'd like something that's not there? Just tell us what, we'll see what we can do.

About light path expressions

Unread postby square01 » Thu May 18, 2017 12:40 am

Hi,
thank you for having this feature,
I dont know about whats happening on 3.5, but on Deadulus I have to create node and assign the expressions.
Having LPE is really powerful , but I really dont like them being a separate workflow from AOVS.
The basic AOVS should also be just LPE out of the shelf create by Isotropix.

Have a look at Iray
https://www.lightworkdesign.com/images/ ... sions.html

and Arnold
https://support.solidangle.com/display/ ... ssion+AOVs

They are the AOVs and the AOVs are LPE.

So please dont create 2 different systems, merge the 2 having some already by default, and allowing the user to create whatever by editing the Channels Layers and builting there they own LPE.

Thank you

Johnny
square01
 
Posts: 42
Joined: Sat Jan 26, 2013 12:33 am

Re: About light path expressions

Unread postby sam » Thu May 18, 2017 6:14 pm

Hi Johnny,

You seem to mix multiple concepts at once. What you call AOVs are in fact Image Channel Layers (pretty much what you have in nuke)
These Image Channel Layers are buffers that can be declared manually using Image > Edit Channel Layers... or automatically by nodes (image, materials, renderers etc...)

In Clarisse there are 2 types of AOVs: builtins and customs one.

Builtins are automatically declared by materials which declare their own Image Channel Layers to use them as buffers to store the value of their builtin AOVs. For the sake of simplicity, there's a 1:1 correspondance between the AOV name and the Image Channel Layer one.

Customs are defined by AOV Store on which you can output part of your material network. However where do you store the result of an AOV Store? Simple, in a Image Channel Layer you specify in the AOV Store.

For LPEs this is kinda the same principle as AOV Store except that they are declared at the integrator level. You create a LPE node on which you type an expression and choose a Image Channel Layer to store the result.

In the AOV Editor you then have to select which Image Channel Layer you wish to compute/output in your 3D Layer (note that the ones that are not actually available in the LPE, Material subgraph are greyed out). Also, you can note that an AOV Store or a LPE can override the content of a builtin AOV by specifying the Image Channel Layer name defined by a material for example.

In a nutshell you have named buffers (Image Channel Layers) that are used by Materials, LPE, AOV Store to store informations collected during rendering.

Hoping this clear things up,
Sam Assadian
Isotropix
CEO/Founder
User avatar
sam
 
Posts: 977
Joined: Sat Jan 26, 2013 12:33 am

Re: About light path expressions

Unread postby square01 » Mon May 22, 2017 1:40 pm

Hi Sam,
thank you for explanation .
I understand they are different.
For example with AOV in clarisse I'm able to store them in a cfg and use them all the time,
on LPE I have to have a .project saved with all the LPE nodes.
Maybe I just need to spend a bit more time exploring the LPE sys in Clarisse.

I will play a bit more with it, I'm just waiting for 3.5 now
square01
 
Posts: 42
Joined: Sat Jan 26, 2013 12:33 am

Re: About light path expressions

Unread postby sam » Mon May 22, 2017 7:41 pm

One thing you could do is modify your startup scene to reference a project defining your most used LPEs.
Sam Assadian
Isotropix
CEO/Founder
User avatar
sam
 
Posts: 977
Joined: Sat Jan 26, 2013 12:33 am


Return to Feature Requests