# Octane_Test

Member

17

106 Neutral

• Rank
Member

• Interests
DevOps
Programming
1. ## Friction and damping properties not affecting physics body

I am developing a mini golf game in Scenekit. I have applied dynamic physics body to the ball and static physics body to the grass surface and the brick walls show in this image. Issue: When I apply the force to the ball, the ball’s linear and angular speeds change as shown in the graphs. The ball’s speeds don’t reduce to zero (so that the ball can stop) but remains constant after certain value. Ball linear speed graph Ball angular speed graph Analysis Tests: When I increase the values to both the rolling friction and the friction, the ball speed is reduced quickly but remains constant after certain value (similar to the above graphs). When I increase the values of the linear damping and the angular damping, the ball speed behavior is same as the point #1. When I set the gravity value to -9.8 m/s2, the ball’s linear speed remains constant after 0.1 m/s. If I reduce the gravity value to -5 m/s2, the ball’s linear speed remains constant after 0.05 m/s. The friction, linear friction, linear damping and angular damping are same throughout the motion of the ball. There is 1 millimeter overlapping between the ball and the surface of the golf course. Questions: From the analysis test #3, I think the gravity is causing the constant ball speed issue. Is my assumption correct? If yes, how can I fix the issue? I can’t remove the gravity field as without the gravity field the ball will not roll along the grass and it will slide. Why the friction and the damping properties are not affecting the ball speed after certain value? Are there any other physics properties can cause such issue? From the analysis test #5, are there any chances that the ball is receiving upward push to correct the position of the ball? Solutions: If I increase the physics timestep from 60 FPS to 200 FPS, the issue is resolved. I am not able to understand how this change can fix this issue? After reducing the gravity value to -1 m/s2 and physics simulation speed to 4 (4 times fast physics simulation), the issue is fixed. Again, I am not able to understand how this change fix the issue? I would appreciate any suggestions and thoughts on this topic. Thank you.
2. ## Setup golf ball physics

Thank you for the reply. Yes, Scenekit has the rolling resistance property. Even if I increase the rolling friction of the ball to 1.0, the ball continues to move along the grass surface. Changing velocities at each time step will be same as linear damping and angular damping, right? I have already tried changing those values without success.
3. ## Setup golf ball physics

I am developing a simple Golf game (using Scenekit) as shown in the below image. I am facing below issues: 1. Even if I apply small amount of force, the ball continuous move along the grass? Grass friction is not stopping the ball. 2. Sometimes, the ball speed is increased after colliding with the walls instead the ball speed should decreased after collision with the walls. The walls are having box collider. 3. Sometimes, the ball reverses its direction after colliding with walls. Code: Physics properties of the ball: ball.physicsBody.affectedByGravity = true; ball.physicsBody.mass = 0.0450; ball.physicsBody.restitution = 0.8; ball.physicsBody.friction = 0.3; ball.physicsBody.allowsResting = true; Physics properties of the grass: golf.physicsBody.friction = 0.8; Physics properties of the walls: leftWall.physicsBody.friction = 0; leftWall.physicsBody.restitution = 0.8; I have set the physics world gravity value to -9.8. I am looking for suggestions to fix the above listed issue. Thank you.
4. ## Designing collider for a table with a hole in it

Does the ghost vertices concept exist in 3D engines? If yes, can you please give reference of any such engine?
5. ## Designing collider for a table with a hole in it

Thank you for the reply. Can you explain about how to handle the scenario when the ball is moving too fast over the golf hole?
6. ## Designing collider for a table with a hole in it

Yes, it is a Golf game.
7. ## Designing collider for a table with a hole in it

Thank for the reply. I liked the ideas you described in point #2 and #3. I will give it a try and see if that fixes the problem. Regarding #4, I would like to have a proper circular hole.
8. ## Designing collider for a table with a hole in it

I want the help to design the collider shape for a table. This table has a hole at its center. The table mesh file itself has the hole. The collider design should be such way that the ball can fall into this hole. My thoughts: I think the concave shape collider will be appropriate as it will be exact replica of the mesh file. I am looking for some suggestions about what collider shape will be good enough for my requirements. Golf Course with hole:
9. ## Algorithm Collision physics error

I am working on a game developed using Scenekit (iOS). I am facing some strange issues with collision physics. I have added one 3D table (with a hole at its center) to the scene. I am setting physics shape of this 3D model using following code: SCNBox* tableBody = [SCNBox boxWithWidth:(5*golf.scale.x) height:(0.5*golf.scale.x) length:(9*golf.scale.x) chamferRadius:0]; table.geometry = tableBody; //table geometry //physics shape scale NSValue *shapeScale = [NSValue valueWithSCNVector3:SCNVector3Make(table.scale.x, table.scale.y, table.scale.z)]; //physics shape options NSDictionary *shapeOptions = [NSDictionary dictionaryWithObjectsAndKeys:shapeScale,SCNPhysicsShapeScaleKey,SCNPhysicsShapeTypeConcavePolyhedron,SCNPhysicsShapeTypeKey, nil]; //physics body table.physicsBody = [SCNPhysicsBody bodyWithType:SCNPhysicsBodyTypeStatic shape: [SCNPhysicsShape shapeWithNode:table options:shapeOptions]]; I am adding one 3D ball on top of this table. Issue: The Ball collides with 3D table mesh triangles and changes directions I have following questions: How can I stop collision of ball with these lines? Are there any modification to the physics can be done? I want the hole to be part of the physics shape so that the ball can fall into the hole. I would appreciate any suggestions and thoughts on this topic. Thank you.
10. ## Generate unique ID per user

Thank you for the reply. I agree with your suggestion of using GUID (UUID) as User ID. I don't want to generate any identifier based device's hardware so that I don't violate Apple's or Google's guidelines. Given I am fetching local machine's time in milliseconds, what are the chances of collision? Answers matching your questions: No No No I am fine with if a new User ID is generated when a player play the game on other device.
11. ## Algorithm Generate unique ID per user

I am developing a cross platform game for which I needs to generate unique identifier (User ID) for each user. I known some platform (Android or iOS) specific approaches to get device related identifiers but I am looking for a solution independent of the device identifiers. User ID Requirements: 1. Independent of the device's platform 2. Offline implementation (no communication with any servers) 3. Without sign-up process I have implemented one approach to create User IDs where I store the system time when the game was launched for the first time on the device. I have following questions: 1. Are there any other approaches to generate User IDs (which will meet the above requirements)? 2. What are the common approaches to create unique identifiers with taking any information from the user? 3. Are there any third party plug-ins to implement User IDs? I would appreciate any suggestions and thoughts on this topic. EDIT: There are lot of responses to use UUID/GUID. Generally, this approach looks fine but I am looking for a solution which can generate same User ID even if the user reinstall the game.
12. ## Game AI architecture for a RTS game

Thank for your response Alvaro. Are talking about "Goal oriented AI"? The AI in which actions are taken to meet the immediate needs/goals. Will there be any advantage of using decisions trees instead of rule based system?
13. ## Game AI architecture for a RTS game

I am developing a RTS game involving robber and cops. I have designed a simple rule based AI system for the robber. Goals of the robber AI: Escape from the cops (robber should not get caught) Conduct robbery Current implementation: The robber AI uses a rule based system to escape from the cops. I have written IF-THEN clauses to build the rule based AI system. The robber AI uses the knowledge of cops’ current positions. Future requirements: I am worried about the current architecture of this robber AI system. I read that rule based systems are inefficient and difficult to maintain. For the future, I want the robber AI to use some power-ups (to escape) The AI should consider the power-ups used by the cops before making decisions. For conducting the robbery, the robber has to move to a specific location escaping from the cops. Questions: Is the current rule based AI system will flexible enough (and easy to maintain) to meet the future requirements? What can be better alternatives for the existing rule based system? (Like decision trees or state machines etc.) I read people suggesting that the rule based systems are difficult to debug. Can anyone explain why? I would appreciate any thought/suggestions on this topic. Thank you.
14. ## 3D mesh explosion in Cocos2D-X

I am developing a 3D game with Cocos2D-X. I want to implement the functionality of exploding 3D mesh file into its components. I found that Cocos2D-X currently does not include the feature of destructible mesh similar to other game engines. As per the 3D documentation on Cocos2D-X website, Cocos2D-X currently supports Particle Universe Editor for creation of the 3D particle effects, but the domain for download link of Particle Universe Editor is expired (Mirrors also lead to expired domain). I am able to use the in-built explosion 3D particle system in Cocos2D-X, but I want the texture of exploded particles to be the same as the mesh texture.   I have the following queries:   1) Does anyone have the working link for downloading the Particle Universe Editor?   2) Are there any other alternative tools/plug-ins for creating 3D mesh explosion for Cocos2D-X?   3) Also, are there any other good approaches for implementing 3D mesh explosion functionality in Cocos2D-X?   I’d appreciate any suggestions on this issue. Thank you in advance.
15. ## Physics and collision detection libraries for a 3D game in Cocos2D-X

Hi @rraallvv,   Thank you for the reply. I will try to use bullet physics in my project and thank you for the example link.