pmndrs/cannon-es

CANNON.Ray(...).intersectBody doesn't update direction itself

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#15 opened on Apr 6, 2020

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enhancementhelp wanted

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Description

new CANNON.Ray(vFrom, vTo).intersectBody(body) method doesn't work without using ray.updateDirection method (which was private in cannon.js).

body.addEventListener("collide", ({ contact }) => {
  if (!grounded) {
    const vFrom = body.position;
    const vTo = new CANNON.Vec3(0, -1, 0);
    const ray = new CANNON.Ray(vFrom, vTo);
    ray.updateDirection(); // <------ I shouldnt need to update the direction 
                            //         manually before using intersectBody
    ray.intersectBody(contact.bi);
    grounded = ray.result.hasHit;
  }
});

A bug also encountered here but you should dig into the code.

Also, thanks for your port and fork !

Contributor guide

Research direction
Look at the Ray constructor to see how it stores from and to vectors, then trace the intersectBody method to understand why direction is not updated automatically.
Tech stack
typescript
Domain
game dev
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
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Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
TypeScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75