HISE itself build succeeded.

Using VSTSDK3613(20190804, Xcode 10.3, macOS 10.14 Mojave 2nd Supplemental Update. macOS SDK is the one shipped with Xcode 10.3 update.
HISE Source Code git commit number is 8ef678e with only the replacement of the Projucer app itself (5.4.4).

Solution: If seeing lines triggering the "Redefinition of iid" issue, simply comment out those lines.

The new problem is that I don't know the further steps within the HISE environment to build VST3.

@ustk

I did everything you said (except that VST3 support is checked through Projucer preferences of the HISE standalone project), it doesn't work.

I don't think it is because of you personally. Instead, if VST3 is being respected enough by this world, things shouldn't be terrible like this.

What's the exact git commit number of the HISE source code you are using? What VST3 SDK version are you using for your successful compilation of VST3-supported HISE (still 3.6.6)? What's the version of Projucer you are using? What's your macOS system build number? What's the Xcode version you are using? Which macOS SDK?

@ustk If using the 2016 sdk shipped from the HISE repository (the "repo SDK"), it says the lack of flock.cpp and its h file. I copied them from the latest SDK to the repo sdk, found more numerous build errors.

If I use the latest official SDK, then the issue of [Redefinition of "iid"].

@ustk Doesn't work on my side. I dunno why.
Now I am gonna perform the plugininterfaces trick.

As I see, blaming someone won't work. I just feel really pissed of wasting 12hrs the whole day but still cannot get my virtual instruments compiled in VST3. Really pissed off.

@ustk I am suffering with exactly the same issue as yours now. (Redefinition of "iid".)
Using VSTSDK3613(20190804, Xcode 10.3, macOS 10.14 Mojave 2nd Supplemental Update. macOS SDK is the one shipped with Xcode 10.3 update.
HISE Source Code git commit number is 8ef678e with only the replacement of the Projucer app itself (5.4.4).

The whole industry's attitude towards VST3, while being unchanged since the recent 10 years, is becoming more and more problematic, regardless that similar attitudes of Hart (for example only) and Native Instruments (who refuses to give VST3 a fk constantly even if developing Kontakt 6) is not blamable due to the nature of humanity.

VST2 plugins are nightmares to Steinberg Dorico, which is my main app for music composition and arrangement. Native VST3 plugins runs fine with Dorico 3, but whitelisted VST2 plugins (including some VST2 plugins renamed as VST3) and certain universal-SDK VST23 plugins (like plugins generated by Maize Sampler) can let Dorico crashes like a hell after once successful load. Everytime you start your system and run Dorico, load a plugin like that, it runs fine until you want to turn off Dorico, and you will see Dorico hangs. Then you will find that Dorico is not runnable until you restart your system.

Please, please support VST3 by default. Otherwise I guess it really is the time to let the Cubase / Nuendo / WaveLab product line give up their support of VST2.

Update: The note stuck problem solved. Tick on "fix stuck notes" among all MidiMuters.

Update: I wrote the following and put it into both "oninit" and "onController" of the preset, it works except very fast & frequent pedal movements with fast piano pieces.

var muteup = Synth.getMidiProcessor("muteup");
var mutedn = Synth.getMidiProcessor("mutedn");
function onController()
{
	if (Synth.isSustainPedalDown() == true) {
		muteup.setAttribute(0, 0);
		mutedn.setAttribute(0, 1);
	}
	if (Synth.isSustainPedalDown() == false) {
		mutedn.setAttribute(0, 0);
		muteup.setAttribute(0, 1);
	}
}

@Christoph-Hart Thank you for your reply. Unfortunately, when I copied the snipped and tried to load it in HISE on my Mac Pro (mojave 10.14.6 2nd supplemental update, latest HISE public release at this moment), HISE simply reloads a new blank preset.

I am migrating one of my Piano SFZ instruments to HISE in order to make it standalone.

The original SFZ instrument utilizes two groups of samples: PedalUp and PedalDown. When Sustain Pedal is pressed, only the PedalDown group articulates; When Sustain Pedal is not pressed, only the PedalUp group articulates.

Is there any necessary scripting steps? I am totally new to HISE.