Feedback Obi 8: what's coming up

[josemendez]

Hi!
This sounds like greate feature, exactly what I wanted  
In my opinion providing ways to customize obi is great step and anything that allows to customize particles, forces constraints is really great tool.

I have got questions about managing constraints and additional helpers related to that.
1. Is it possible to show inspector in obi actors? So for example in obi softbody next to shape constraint to have some options for particles?

Actors can implement a IConstraintUser interface (name might change) that exposes parameters related to that constraint in the inspector. This is similar to how we currently do it, but want to expose this cleanly in the new API. Which options about particles would you like to see exposed in the inspector?

2. I guess by default those constraints are added from code, so dedicated component could be created to manage adding batches, something like stich constraint?

Constraints can come from:
A)  a blueprint
B)  a custom component (like ObiParticleAttachment or ObiStitcher)
C)  at runtime from particle-particle or particle-collider neighboring information (like contact constraints)

There will be helper APIs for common tasks like graph coloring (to generate batches from a list of constraints), segmented prefix sums for binning constraints, stream compaction, etc. But yes, we're focusing on providing tools to do this from code. If you wanted a component to add specific constraints at runtime, you can write that (would be option B) in the above list)

3. Would it be possible to create custom actor? For example custom, different type of softbody that uses different rules, structure, constraints?

Yes, you can technically do this right now but we want to clean up the API, put safety fences and thoroughly document it so that the correct workflow is easy to understand and follow.

4. What about order of execution? Can I control when custom constraint is executed? By this I mean obviously substeps, to make my constraint to execute as last or before other constraint.

Yes, each constraint type has a "priority" (an integer number) that determines its relative update order. You define its value when deriving from ObiConstraintData, in the above examples see the ObiBendConstraintData class:

Code:

public override int priority => 100;

Ideally we want to allow constraints in the ObiSolver inspector to be drag/dropped to be reordered too (like in Unity's Script Execution Order window), so that you can modify the default priority on a per-solver basis for specific scenarios.

cheers!