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Advanced Camera Modifications

by Chris French · in Torque Game Engine · 09/16/2006 (1:32 pm) · 8 replies

This is a snipet of the advanced camera code that gets the position for the 3rd person camera. Im trying to create a camera for a sidescrolling shooter using the meat from this camera. The problem i'm havin is that when i flip the player model(turn him 180 degrees) the camera switches sides as well (Stays over the right shoulder). What i want the camera to do is use the world positioning so that the camera doesn't switch sides based on what direction the player is facing. Im pretty sure the change needs to be made "objToWorld = playerObj->getRenderTransform();" in there... but im not exactly sure how do it. How exactly do i get the player coordinates and keep them in world coordinates so that i can move the camera using world coords but still have the player as a origin point?


case ThirdPersonMode :
		{
			if(	playerObj != NULL )	{
				MatrixF	objToWorld;
			objToWorld = playerObj->getRenderTransform(); // gets a MatrixF of mRenderObjToWorld from sceneObject
			objToWorld.mulP(mCurrentThirdPersonOffset, &cameraPosWorld); // sets Camera Position using Player coords(mat) and offset(p3F)
			}
		
			break;
		}
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Torque 3D Owner Chris French
#1
09/17/2006 (4:24 pm)
I guess what im looking for is a better understanding of the following variables and their uses.

MatrixF mObjToWorld;   ///< Transform from object space to world space
   MatrixF mWorldToObj;   ///< Transform from world space to object space (inverse)
   Point3F mObjScale;     ///< Object scale

   Box3F   mObjBox;       ///< Bounding box in object space
   Box3F   mWorldBox;     ///< Bounding box in world space
   SphereF mWorldSphere;  ///< Bounding sphere in world space

   MatrixF mRenderObjToWorld;    ///< Render matrix to transform object space to world space
   MatrixF mRenderWorldToObj;    ///< Render matrix to transform world space to object space
   Box3F   mRenderWorldBox;      ///< Render bounding box in world space
   SphereF mRenderWorldSphere;   ///< Render bounxing sphere in world space

But im guessing a lot can be said so i'll try to be more specific.

i want to get the player objects world coords and adjust those coords and set them for the camera. Looking at the code in sceneobject has me wondering if resetWorldBox(); is screwing up what im trying to do... not sure.

Torque 3D Owner Chris French
#2
09/18/2006 (10:14 am)
Please let me know if anything is unclear or perhaps I need to rethink my questions(are they too broad).

Torque 3D Owner Chris French
#3
09/19/2006 (11:05 am)
Here is an image of what i am talking about:

lh4.google.com/chrisfrenchphotos/RRAwu-mQABI/AAAAAAAAAMs/9V6XEmVIbQo/camera.jpg
edit: wierd... i can get it not to work on my computer??? tried clearing cookies, cache, used different browsers... idk

Torque Owner Tim Heldna
#4
09/19/2006 (11:07 am)
Image isn't working.

Associate Kyle Carter
#5
09/19/2006 (10:29 pm)
What problem are you trying to fix? Can you give a succinct explanation of what's going wrong?

Torque 3D Owner Chris French
#6
09/20/2006 (10:13 am)
I have the camera offset on the x axis 30 units from the player (straight out from the players right side). When i do a transform on the player, with a key bind, to turn him 180 degrees (face the opposite direction), the camera switches sides (continues to look over the right shoulder). It seems as if, when the player rotates 180 degrees to turn around so does the coordinate system that the camera is using to position itself.

Does this help explain the situation?

Associate Kyle Carter
#7
09/20/2006 (10:20 am)
The third person camera is tracked as being relative to the player. So if the player moves, it will, too.

Torque 3D Owner Chris French
#8
09/20/2006 (10:36 am)
Would it be sloppy to mulitiply the offset by -1 everytime he switches direction... it seemed hackish to me but i suppose until i can figure out a way to do it in the C++ camera code, the script hack will have to work.