IBL Texture Environment Best Practices Tweet

[prehabitat]

Hi,

I usually use Revit sun for my renders because my professional stuff is mostly sun studies and a few token images which I'm ashamed to say I post-edit them to acceptable levels (the photorealistic rabbit-hole has proved too deep to date). I'm currently trying to get IBL working in aid of adding believable reflections in windows to add one more step towards believable photorealistic.

Can I have some input into best practices/settings? Current settings which seem reasonable are:
Environment [Texture environment]
-Texture: [RGB Image]: Skies2_etc etc.hdr
-Power: [Greyscale Image]: 1
-Gamma: [Float Value]: 2.2
-Invert: [Bool Value]: Disabled
-UV Transform: [3D Transformation]
->Rotation Order: [YXZ]
->Rotation: [Float Value] : <to suite building siting>
->Scale: [Float Value] : 1
->Translation: [Float Value] : 0
-Projection: [Spherical]
->Sphere Transformation: [3D Transformation]
->>Rotation Order: [YXZ]
->>Rotation: [Float Value] :
->>Scale: [Float Value] : 1
->>Translation: [Float Value] : 0
->Coordination Space: [Enum Value]: Object Space
-Border Mode: [Enum Value]: Wrap Around
-Power: 2 (its an overcast image)

Other Settings:
Exposure: [Float Value]: 1

Alpha Channel: [Bool Value]: Disabled *
Keep Environment: [Bool Value]: Disabled *

*I read the manual, but I'm having a dense moment with this: am I right in saying that you only use(Read ENABLE) Alpha Channel if you want to composite the image later (which is what I previously did in photoshop after using Revit sun) and you only also use Keep Environment (Read: Both ENABLED) if you want to keep the reflections of the environment?

A Few Specific Questions: I get a lot of dark areas (under eaves, canopys etc.. almost black in places) despite being on the side of the house immediately facing the sun sot on the HDR and having power and exposure turned up - is this normal?

I have been using the uv transformation to rotate the image, does the sphere transformation do anything? or would that be for rotating the cube/perspective projection? (but not the image wrapped to it, which is rotated with the UV Transformation Rotation ... correct??)

Also, is | Power: [Greyscale Image]: 1 | the correct method for powering the IBL?
In the revit manual says Power should be set to [Image]: but that's already been done with [RGB Image] in the texture node? (manual has older nodes, was confusing).
Furthermore, Can | Power: | be any of the following assuming the situation calls for it?
-[Greyscale Image]: 1
-[RGB Image]: <as above> (seems to amplify the colours - which makes sense)
-[Alpha Image] : <image as above. (seems to work, amplifies the light intensity, but adds two rotation variables, which I'd rather not deal with...)
-anything else???

anything else anyone noticed?

EDITED: typo & added some Texture Enviuronent | Power Node questions

[face_off]

If you are using a .hdr file, set the gamma to 1 - that should significantly change the look of the render. The power can then be dropped from 2 to 1.

From memory - Keep Environment is removed in the next release (built with Octane 2.20). You can render the Beauty pass (with alpha channel enabled) and separately save out the Environment pass, and then compose in photoshop tweaking the power of each to get the effect you want.

Yes, the Spherical projection Y slider is used to rotate the IBL.

Paul

[prehabitat]

If you are using a .hdr file, set the gamma to 1 - that should significantly change the look of the render. The power can then be dropped from 2 to 1.

From memory - Keep Environment is removed in the next release (built with Octane 2.20). You can render the Beauty pass (with alpha channel enabled) and separately save out the Environment pass, and then compose in photoshop tweaking the power of each to get the effect you want.

Yes, the Spherical projection Y slider is used to rotate the IBL.

Paul

OK, thanks for the tips, I'll try that tonight.

I'm using Octane 2.20 already, so I'll keep an eye out for that; since I'm familiar with compositing the background in anyway I may do the passes, thanks Paul.

lastly, Spherical Projection Y Slider =
-Projection: [Spherical] ->Sphere Transformation: [3D Transformation] ->>Rotation: [Float Value] : ???

I should ignore the UV Transformation?
(-UV Transform: [3D Transformation] ->Rotation Order: [YXZ] ->Rotation: [Float Value] : <to suite building siting>)

Sorry for the ultra-specific. I really want to nail down some safe options which mostly work which I can then add to as I develop my understanding of all the overlapping concepts we're dealing with

Also, have you ever considered a Presets system? it could perhaps replace the clay render mode button, and perhaps have user definable preset slots?
or does something else already capture this kind of functionality (Save Render Target perhaps?)

[face_off]

lastly, Spherical Projection Y Slider =
-Projection: [Spherical] ->Sphere Transformation: [3D Transformation] ->>Rotation: [Float Value] : ???

I should ignore the UV Transformation?
(-UV Transform: [3D Transformation] ->Rotation Order: [YXZ] ->Rotation: [Float Value] : <to suite building siting>)

Yes - use the former to rotate the IBL. In most situations you can ignore the IBL UV Transformation (rotation and translate does nothing, scaling scales the IBL but IMO not in a good way).

Also, have you ever considered a Presets system? it could perhaps replace the clay render mode button, and perhaps have user definable preset slots?
or does something else already capture this kind of functionality (Save Render Target perhaps?)

Yes, import/export rendertargets and saving to Views is designed to do exactly that. Unfortunately clay mode is not an Octane "pin" on a node, so doesn't get saved to the View/rendertarget.

Paul

[prehabitat]

Yes - use the former to rotate the IBL. In most situations you can ignore the IBL UV Transformation (rotation and translate does nothing, scaling scales the IBL but IMO not in a good way).

Ok, crystal clear, thanks Paul

Yes, import/export rendertargets and saving to Views is designed to do exactly that. Unfortunately clay mode is not an Octane "pin" on a node, so doesn't get saved to the View/Rendertarget.

OK, I was thinking more along the lines of a drop-down list with:
<Defaults> (default),
Clay Mode (fast),
Clay Mode (light study),
Fast Beauty,
etc

Kinda like the presets in Revit rendering I suppose: Might be a nightmare to implement. and no one else might want it..