[m-Que]

Hey,
I just ran into this weird issue:

The Setup - a sphere an a plane with glass material applied;
Environment - IBL (just a simple backplate);


1. 'Screen mapping' DISABLED (all OK):


2. 'Screen mapping' ENABLED (not OK):


Am I doing something wrong or this is some kind of issue?

Thanks.

[tom]

"Screen Mapping" is an option for background mapping. You cannot flatten out the whole virtual space. It's simply always spherical.

[m-Que]

Oh, OK. Got it.
Is there a way to achieve it via specific render channels and composite things later together?

[tom]

You really need the HDR dome (latitude map) for that backplate image to illuminate your scene. Attemping to use the backplate image for other 3 channels (illum/refl/refr) makes no sense as it violates the purpose of IBL illumination. Also maybe you're interested in joining this? http://www.maxwellrender.com/gallery/ma ... ompetition

[m-Que]

Thanks for the info, Tom.
The point was that the client came with a hires backplate and wanted things to be composed to it.
So, there where some see-through windows and that effect has appeared...
Now, I guess I'll just throw a plane with a backplate applied to it, or render alpha and do the composting in PS.
After all, the task was to 'make it look cool'
Also thanks for the tip regarding competition - that will be a great exercise

[dariolanza]

Hi m-Que,

In order to achieve what you are looking for, my suggestion is to create a hidden planar object, filling the whole frame, and texture in camera projection mode (you will have to set it in your 3D platform).
Once textured in camera projection with the background image, simply hide that object to camera while keeping it visible to reflections/refractions (secondary rays).

This way, it wont' be directly visible by the camera, but it will be visible through the transparent objects, while keeping the camera projection as you want.

In addition to that, you will be able to adjust the brightness of that texture map (in the Reflectance 0 slot of that material), for a custom match of the brightness of that refractions.

Let me know if this is helpful.

Greetings

Dario Lanza

[m-Que]

Thank you for the tip, Dario.

Actually, I'm working in MaxwellStudio. Is 'camera projection mode' available/possible within Studio?