Search found 17 matches

by whitwhoa
Sun Feb 20, 2022 1:17 am
Forum: General Bullet Physics Support and Feedback
Topic: Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)
Replies: 5
Views: 7295

Re: Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)

Alright, so that didn't work. But I believe my logic to have been sound, I just didn't take into consideration collision margins. I took my spherecast position and then generated a ghost object slightly in the opposite direction of the contact point (so that it would intersect the geometry which the...
by whitwhoa
Fri Feb 18, 2022 8:10 pm
Forum: General Bullet Physics Support and Feedback
Topic: Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)
Replies: 5
Views: 7295

Re: Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)

After some more research I found the following thread where Erwin explains how the `m_hitNormalWorld` is calculated. I believe I've come up with a solution for my particular use case that will provide me with the data that I require, however I've yet to implement it to confirm. If it works as I expe...
by whitwhoa
Wed Feb 16, 2022 3:21 am
Forum: General Bullet Physics Support and Feedback
Topic: Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)
Replies: 5
Views: 7295

Re: Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)

I have written a few character controllers that had special logic for walking up ledges and sliding down slopes. They were always dynamic controllers rather than kinematic... As I recall, I ended up with complicated tuned systems. THIS. THIS exactly. The reason I started work on a kinematic control...
by whitwhoa
Tue Feb 15, 2022 4:22 am
Forum: General Bullet Physics Support and Feedback
Topic: Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)
Replies: 5
Views: 7295

Obtaining multiple face normals from convexSweepTest? (to determine stepping vs sliding for kinematic controller)

Hello again! If anyone reading this has seen my other posts I've made recently you've probably gathered that I've been working on implementing a kinematic controller. I've started from scratch more or less using btKinematicCharacterController as a reference and implementing the most basic pieces fir...
by whitwhoa
Fri Feb 04, 2022 10:09 pm
Forum: General Bullet Physics Support and Feedback
Topic: Recalculate local origin of btCompoundShape?
Replies: 2
Views: 4313

Re: Recalculate local origin of btCompoundShape?

Greatly appreciated! Was able to get it worked out. Also came across this gist while researching what you had explained, which helped out as well. :)
by whitwhoa
Thu Feb 03, 2022 10:45 pm
Forum: General Bullet Physics Support and Feedback
Topic: Recalculate local origin of btCompoundShape?
Replies: 2
Views: 4313

Recalculate local origin of btCompoundShape?

Curious if there is a way to recalculate the local origin of a btCompoundShape? I currently have a shape consisting of two spheres and a cylinder, however the origin of the btCompoundShape seems to be the origin of one of it's child shapes and not the origin of the aabb for the compound shape. Below...
by whitwhoa
Sat Jan 29, 2022 8:50 pm
Forum: General Bullet Physics Support and Feedback
Topic: Manual penetration recovery using aabb of penetration vectors
Replies: 1
Views: 3591

Re: Manual penetration recovery using aabb of penetration vectors

OK, so I misunderstood what was meant by "origin" in that original post. I was thinking they were referring to the origin of the AABB, but they're referring to the origin of the world. Generating an AABB around your penetration vectors and finding the corner with the greatest length then y...
by whitwhoa
Fri Jan 28, 2022 5:10 am
Forum: General Bullet Physics Support and Feedback
Topic: Manual penetration recovery using aabb of penetration vectors
Replies: 1
Views: 3591

Manual penetration recovery using aabb of penetration vectors

I seem to be running into the issue that was discussed in this thread . The op indicates that the proposed solution of generating an aabb around the penetration vectors and then using the corner that is furthest from the origin of the aabb "works". However, I'm confused as to what the corn...
by whitwhoa
Wed Aug 26, 2020 3:58 pm
Forum: General Bullet Physics Support and Feedback
Topic: Bullet Physics resetting rigidbody origin after manually setting
Replies: 1
Views: 2279

Re: Bullet Physics resetting rigidbody origin after manually setting

Resolved this by completely removing, resetting, and readding the rigid body to the dynamics world via the following: if (this->input.keyLeftControl && !this->crouching) { this->crouching = true; this->crouchNeedFall = true; //Set scale btVector3 scale = this->clientBody->getCollisionShape()...
by whitwhoa
Wed Aug 26, 2020 3:16 pm
Forum: General Bullet Physics Support and Feedback
Topic: Bullet Physics resetting rigidbody origin after manually setting
Replies: 1
Views: 2279

Bullet Physics resetting rigidbody origin after manually setting

Working on a character controller in Bullet Physics engine that uses a rigidbody, specifically crouch functionality. I've run into an issue where Bullet is resetting the origin of the world transform for the body back to what it was before I set it manually. This appears to be happening when stepSim...
by whitwhoa
Sat May 23, 2020 2:48 am
Forum: General Bullet Physics Support and Feedback
Topic: debug draw out of sync with render mesh
Replies: 1
Views: 2582

Re: debug draw accuracy

For clarification I have uploaded a video which shows what I am trying to explain. It maybe an issue with how I'm applying the rotation to my model??? Video Link: https://youtu.be/2TegYEq812g I'm basically just copying the world transform every tick like such: glm::vec3 bodyTranslation = glm::vec3(c...
by whitwhoa
Fri May 22, 2020 9:32 pm
Forum: General Bullet Physics Support and Feedback
Topic: debug draw out of sync with render mesh
Replies: 1
Views: 2582

debug draw out of sync with render mesh

Is there a setting that I am overlooking that determines how frequently the debug lines are drawn by the debug drawer? I have a cube shape rigid body that is updating the translation and rotation of a cube object to be rendered, but when I enable my debug drawer the lines appear to not be updating a...
by whitwhoa
Thu Jun 13, 2019 4:22 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision shapes appear to have boxes around them
Replies: 4
Views: 4150

Re: Collision shapes appear to have boxes around them

The enum values are powers of 2 and represent binary bits in a numerical value. Multiple modes can be enabled by setting more than one bit. You were returning 3 = 1 + 2 which is both DBG_DrawWirefram e and DBG_DrawAabb . :!: NOW it makes sense! I have never really had a need for bitshifting / bitwi...
by whitwhoa
Thu Jun 13, 2019 1:44 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision shapes appear to have boxes around them
Replies: 4
Views: 4150

Re: Collision shapes appear to have boxes around them

It probably represents the bounding box of the object in the broadphase, which I think can be enabled/disabled but must somehow be enabled for you. This pointed me in the right direction! Greatly appreciated. The issue was from my lack of implementing `setDebugMode` and `getDebugMode` specifically ...
by whitwhoa
Wed Jun 12, 2019 11:42 pm
Forum: General Bullet Physics Support and Feedback
Topic: Collision shapes appear to have boxes around them
Replies: 4
Views: 4150

Collision shapes appear to have boxes around them

Would anyone happen to know why that when I draw my collision objects I'm seeing boxes around them? https://stashcube.com/stackexamples/boxes_around_collision_shapes.jpg The following is how I have created my collision world and added the objects to it: bt_collision_configuration = new btDefaultColl...