Light Rotation bug

Archives Forums/Blitz3D Bug Reports/Light Rotation bug

xmlspy (Posted 2007) [#1]

I have noticed that when you use the command RotateEntity with a light it works only with Pitch. Given values: Pitch: 90 Yaw: 20 Roll: 25 Returned values with EntityPitch, EntityYaw, and EntityRoll commands: Pitch: 90 Yaw: -180 Rol: 180 Some code: Graphics3D 640, 480, 0, 2 cam =CreateCamera() h = CreateLight() RotateEntity h, 90, 20, 25 DebugLog "CHECK: Pitch: " + EntityPitch(h) + " | Yaw: " + EntityYaw(h) + " | Roll: " + EntityRoll(h) WaitKey() End Computer Info: DX9 C ATI Radeon X1950 512 MB - Latest drivers B3D Version: 1.98, Userlibs: none AMD Athlon 64 X2 WinXP Pro [update] Actually the rotation bug applies to any entity, not just lights.

John Blackledge (Posted 2007) [#2]

I came across this a while ago - you have to do an UpdateWorld before asking for values back from EntityPitch() and other such commands. (Mmmm... yes it is, isn't it.:-)

Floyd (Posted 2007) [#3]

This is really about gimbal lock. A rotation like this RotateEntity ent, 90, anything, anything leaves the z-axis pointing directly down, where the negative y-axis used to be. Thus yaw and roll both turn around the same (vertical) axis.

John Blackledge (Posted 2007) [#4]

I repeat: you have to do an UpdateWorld before asking for values back from EntityPitch() and other such commands.

big10p (Posted 2007) [#5]

John: you don't even need to call UpdateWorld unless you're using animation and/or collisions. You can grab the pitch (etc.) of an entity directly after rotating it just fine. The problem here is surely as Floyd describes.

John Blackledge (Posted 2007) [#6]

Answer is as per the other (Terrain) thread. I'm just telling you what works for me.