The engine is ZGameEditor with a wrapper for Bullet Physics Library.
Until now, everything was fine. The player could fly and collide with buildings and enemies made out of collision boxes and spheres. But recently, I started adding pillars that are not vertical and discovered this problem:
When the pillar is vertical or horizontal (fig. A), like a lot of the objects in my game, everything's fine.
But if it's rotated (fig. B), the ball collides with the box that encompasses the rotated pillar...
Code:
shape = zbtCreateCylinderShape(0.5, 10);On the contrary, if the shape of the pillar is "complex", the collision works better, but it's not perfect: the ball gets the collision correctly with the pillar, but then it stays collided as long as the ball stays in the red rectangle.
Code:
shape = zbtCreateCompoundShape();zbtAddChildShape(shape, zbtCreateCylinderShape(0.5, 10), 0,0,0, 0,0,0);I could replace all shapes by compound shapes in my game, but it would be overkill for what it is supposed to do.
I made a working example if you want to try, but here's the general idea:
I heavily simplified the code for readability. As you will see, it's quite simple. I use setPosRot to set the physics of the rotating pillar, and the coordinates of the ball. Then I use isColliding to check if both collides.
Code:
<OnLoaded>// init physical worldxptr World = zbtCreateWorld();zbtSetCurrentWorld(World);// Create modelscreateModel(PillarModel);createModel(BallModel);</OnLoaded> <OnUpdate>zbtStepSimulation(App.DeltaTime, 0, 0);</OnUpdate> <Model Name="PillarModel"><Definitions><Variable Name="PillarBody" Type="xptr"/></Definitions> <OnSpawn>xptr shape = zbtCreateCylinderShape(0.5, 10);PillarBody = zbtCreateRigidBody(1, shape, CurrentModel.Position, CurrentModel.Rotation);</OnSpawn> <OnUpdate>// Rotate the pillarCurrentModel.Rotation.Z += 0.001;zbtSetPosRot(PillarBody, CurrentModel.Position, CurrentModel.Rotation);</OnUpdate><OnRender><RenderMesh Mesh="PillarMesh"/></OnRender></Model><Model Name="BallModel"><Definitions><Variable Name="BallBody" Type="xptr"/></Definitions> <OnSpawn>xptr shape = zbtCreateSphereShape(1.0);BallBody = zbtCreateRigidBody(1, shape, CurrentModel.Position, CurrentModel.Rotation);</OnSpawn> <OnUpdate>// Set Ball position to mouse coordinateCurrentModel.Position = vector3(App.MousePosition.X, App.MousePosition.Y, 0);zbtSetPosRot(BallBody, CurrentModel.Position, CurrentModel.Rotation);// Test collision between ball and rotating pillarif (zbtIsColliding(BallBody)) {BallColor.Color = vector3(1, 0, 0); // red} else {BallColor.Color = vector3(1, 1, 1); // white}</OnUpdate><OnRender> <RenderSetColor Name="BallColor" /><RenderMesh Mesh="BallMesh"/></OnRender></Model>Thanks for your help.
Statistics: Posted by Txori — Fri Oct 14, 2022 5:17 am
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