Can't get mesh picking to work with modified transform on model

[Pirolye]

Hi,

I have a struct which contains a model. The struct has a function to update the transform of the model so I don't have to do it manually all the time.

I also have a mesh picking system wherein the world struct sends out a request to all entity structs to check against their own models or anything that I want to include in the selection process.

This works perfectly for models that have { 0 } transforms. Anything else doesn't work.

The collision check is failing at line 3683 of rmodels.c ( if ((u < 0.0f) || (u > 1.0f)) return collision; )

Transform change algorithm: (enttTransform is a struct with 2 Vector3s and a float, not connected to anything)
`

cubeModel.transform = MatrixMultiply(cubeModel.transform, MatrixScale(enttTransform.scale, enttTransform.scale, enttTransform.scale));
cubeModel.transform = MatrixMultiply(cubeModel.transform, MatrixRotateXYZ(Vector3{ DEG2RAD * enttTransform.rot.x, DEG2RAD * enttTransform.rot.y, DEG2RAD * enttTransform.rot.z }));
cubeModel.transform = MatrixMultiply(cubeModel.transform, MatrixTranslate(enttTransform.pos.x, enttTransform.pos.y, enttTransform.pos.z));

`

Here's how the entity in question deals with the pick request: (This works fine)

`

RayCollision meshHitInfo = { 0 };
for (int m = 0; m < cubeModel.meshCount; m++)
{
	// NOTE: We consider the model.transform for the collision check but 
	// it can be checked against any transform Matrix, used when checking against same
	// model drawn multiple times with multiple transforms
	meshHitInfo = GetRayCollisionMesh(inRay, cubeModel.meshes[m], cubeModel.transform); // FAILING ON NON-ZERO TRANSFORMS
	if (meshHitInfo.hit)
	{
		
		return this;

		break;  // Stop once one mesh collision is detected, the colliding mesh is m
	}
	else
	{
		return nullptr;
	}
}

`

I have gone through step-by-step all 3 algorithms (transform change -> collision check request -> rmodels.c collision check, although I don't understand that one)

Here's how the model's transform looks after the change algortihm: (Scaled down and moved a bit)

It would be greatly appreciated if someone could nudge me in the correct direction,
Pirolye

[chriscamacho]

just a thought, are you setting the transform to identity? as

cubeModel.transform = MatrixMultiply(cubeModel.transform, MatrixScale(enttTransform.scale, enttTransform.scale, enttTransform.scale));

will be picking up the previous state of the transform...

[Pirolye]

I'm afraid I don't understand how to do that. The docs don't have anything and I can't decode it from the headers...

[Pirolye]

Update 1: I now understand the suggestion. I won't worry about that for now.

Update 2: It looks like ray's algorithm is wonky as from certain positions I am able to select the cube with the modified transform. Checked the code again, the transform is applied and passed down correctly everywhere.

[Pirolye]

This is the current standing. Please ignore the red lines, they are not used anymore.

[Pirolye]

Update 3: I tried to manually update bounding box positions since mesh collisions are broken. I tried (+variations) these 2 algorithms:

`

BoundingBox entityBox = BoundingBox
{ Vector3 
	{
		enttTransform.pos.x - enttTransform.scale / 2,
		enttTransform.pos.y - enttTransform.scale / 2,
		enttTransform.pos.z - enttTransform.scale / 2
    },
	Vector3 
	{
		enttTransform.pos.x + enttTransform.scale / 2,
		enttTransform.pos.y + enttTransform.scale / 2,
		enttTransform.pos.z + enttTransform.scale / 2
	} 
};

selectionBoundingBox = entityBox;

/*

selectionBoundingBox.min = Vector3Scale(selectionBoundingBox.min, enttTransform.scale * enttTransform.scale);
selectionBoundingBox.max = Vector3Scale(selectionBoundingBox.max, enttTransform.scale * enttTransform.scale);



//Vector3 bruh = { enttTransform.scale / 2.0f, enttTransform.scale / 2.0f, enttTransform.scale / 2.0f };
Vector3 bruh = { enttTransform.scale, enttTransform.scale, enttTransform.scale };

Vector3 posScaled = Vector3Scale(enttTransform.pos, (enttTransform.scale * enttTransform.scale));

Vector3 aaa = Vector3{ posScaled.x + posScaled.x + posScaled.x, posScaled.y + posScaled.y + posScaled.y, posScaled.z + posScaled.z + posScaled.z };
selectionBoundingBox.min = Vector3Add(selectionBoundingBox.min, aaa);
selectionBoundingBox.max = Vector3Add(selectionBoundingBox.max, aaa);
//Vector3 bbb = Vector3Subtract(aaa, bruh);

*/

`