Enable Toggling Between PBR and Blinn-Phong Materials

[bennettgoble]

Description

Currently, within the Second Life viewer, once a user assigns a Physically Based Rendering (PBR) material to an object, there is no straightforward way to revert that object's material back to the traditional Blinn-Phong shading model. This creates a "one-way street" for material assignment, which is a significant anti-pattern in user interface design and content creation workflows.

This limitation has several negative impacts:

• Loss of Flexibility: Content creators lose the ability to easily experiment with different material types or to revert to a simpler shading model.
• Irreversible Changes: Users might inadvertently apply a PBR material and then find themselves unable to go back, forcing them to recreate objects or accept an undesired material state.
• Confusion and Frustration: The lack of a clear option to toggle between these material types can be confusing and frustrating for both new and experienced creators.

Solution

Allow users to switch between material shading modes.

Screenshots

The current editor prohibits switching back to Blinn-Phong after a PBR material is applied

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[Geenz]

I disagree with this. The fix isn’t to “toggle” - PBR as it is today is incompatible with BP on a fundamental level. The “fix” you’re looking for is adding support for PBR specular- which is a different shading model to what we use today. Blinn phong is based upon the same ideas as PBR specular, but with some (frankly unnecessary) tweaks. It can also coexist with PBR metallic (which is what we use) and can be used with it.

[Hecklezz]

In Firestorm, I implemented it so when an object has PBR applied, when you go to the BP tab, locally on the viewer (doesn't update the server) it saves and then nulls out the PBR material so BP correctly displays and can be setup (as a fallback for the decent chunk of users still on pre-PBR). It displays PBR once again if you go back to the PBR tab, teleport away and back, or relog (this behaviour could be worked on/improved).
Everyone else still sees the PBR material at all times, so this doesn't solve the "toggle between the two" feature you mentioned, but is related.

I'm not sure if something similar to this would be desired upstream or not, and the implementation for it is honestly pretty hacky, because as Geenz said, they are not meant to be compatible as it is right now.

[bennettgoble]

Thanks for the context geenz and hecklezz. Right now we have a confusing UI and UX. I'd like us not to surprise people when editing objects, especially if those surprises can cause them to accidentally damage content in a way that can't be undone (ex. editing a non-PBR object, apply a PBR material, unable to change it back.)

@Geenz let's catch up and you can tell me what issue we should have to address this problem, we can write up some tickets together :)