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Determine actor visibility using camera rotation

I trying to draw enemy healthbar over his head. At first I found bounding box that contains enemy:

 FBox boundingBox = EnemyInfoArray[i].Actor->GetComponentsBoundingBox();

Then I project world coordinates to screen:

 pos = Project(EnemyInfoArray[i].Actor->GetActorLocation());

And then use it like this:

 posX = pos.X - mainWidth / 2 + border / 2;
 posY = Project(boundingBox.Max).Y - mainHeight + border / 2;
 
 DrawRect(FLinearColor::Red, posX, posY, healthWidth, mainHeight);

And the problem is that when I rotate my camera (FPS) 180 dergees healthbar still visible on screen. I trying use LineOfSightTo() and GetLastRenderTime() to determine visible actor or not but the both affected only by obstacles not by camera rotation.

How can I fix it?

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Product Version: UE 4.9
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asked Nov 18 '15 at 07:31 PM in C++ Programming

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alebaster
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Finally I check UCanvas::Project() and find that if object behind the screen then result Z-component will be 0. And it works.

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answered Nov 19 '15 at 07:07 AM

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alebaster
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