Proposal: Simultaneous Sound Playback Limit and SL Smoke

[ginga81]

With the recent addition of shadows, I am amazed by the incredible realism.
Given this, I believe the time has come to remove the limit on the number of simultaneous sounds that can be played.

I also think it is time to implement smoke effects—such as those for steam locomotives—that are rendered based on parameters for wind direction and intensity.

#417

S520 is currently treatment of the illness and does not yet appear ready to return to create.
However, I felt that the time might be right for this change.
@adfriz , what do you think?

[ginga81]

The smoke looks very realistic and is already well along in its development; I felt the time had come to finalize and implement it, while simultaneously bringing the sound capabilities up to the same level as the Bve5 parser.

smoke
https://bveworldwide.forumotion.com/t2478-realistic-smoke-trails#22157

[ginga81]

・Linear interpolation of curve geometry and cant for Rail0 and other rails
・Linear interpolation of gradients for Rail0 and other rails

It would be very helpful to be able to implement this in a way similar to the Bve5 parser.
Knowing that fog can be interpolated has been very helpful.