Bone rotation impossible

[Slastraf]

Here is a private video that shows different ways of rotating in Leadwerks and how they all do not work on bones from models.

Moreover, I tried using quaternions to rotate the spider leg around the x axis, which worked but scaled the model up in the process for no reason.
The red, green and blue are rotated on the x , y and z but none of them actually rotate around the x axis. If you set rotation to global, the outcom eis worse.

I am running out of ideas. i have uploaded the spider leg mdl and fbx so you can try yourself.

spider leg.zip

[Josh]

You are constructing a quaternion with 1,0,0, and then using the current time as the w parameter? I actually have no idea what that would do. There is an entire book on the subject of visualizing quaternions. It's called Visualizing Quaternions. I have not read the book yet.

If your angle only involves rotation on one axis then I think you are safe making a Euler rotation and converting that to a quaternion for your target.

[Slastraf]

As far as I understand an quatof xyz = 100 is the "lookAt" vektor of the model and "W" the rotation on that axis (global euler x in that case). if it goes from 0-180 it should turn on that x axis ( It is doing just that, but it should never scale itself up. It is a bug.)

The point is,  neither setQuat or setRot work as they both have inpredictable outcomes.
I am 99% sure that the scaling up issue is a bug so that makes quats unusable in LE currently. Can you confirm that ?

2021-04-15 18-40-56.mkv

[Slastraf]

Here is the quat test file. I am pretty confident it would work normally on any other thing than a bone. But have not tried it there yet.

quatTest.lua

[Josh]

I am 98% sure you are feeding in nonsense quaternions into the command. I don't think they are axis / angle values.

[Josh]

Maybe it should be like this?

	local slerp = a:Slerp(Quat(Vec3(0,0,Time:GetCurrent()*0.05))),self.speed)

 

[Slastraf]

Yeah that pointed me in the right direction, but still not the desired outcome. i will not get a $70 textbook on that so I need to rely on utube now.

[Josh]

Well, try changing the axis that is being modified and I think you will get it.

I don't suggest trying to understand quats. Just use them and know what they are, an unambiguous rotation.

[Josh]

3 minutes ago, Slastraf said:

pointed me in the right direction

[Slastraf]

Here a minimally tested lua funciton to convert from Euler to Quat in LE
source http://www.euclideanspace.com/maths/geometry/rotations/conversions/eulerToQuaternion/index.htm

function eulerToQuat(x,y,z)
    --Assuming the angles are in radians.
    local c1 = Math:Cos(x*0.5);
    local s1 = Math:Sin(x*0.5);
    local c2 = Math:Cos(y*0.5);
    local s2 = Math:Sin(y*0.5);
    local c3 = Math:Cos(z*0.5);
    local s3 = Math:Sin(z*0.5);
    local c1c2 = c1*c2;
    local s1s2 = s1*s2;
	return Quat(c1c2*s3 + s1s2*c3, s1*c2*c3 + c1*s2*s3, c1*s2*c3 - s1*c2*s3, c1c2*c3 - s1s2*s3)
	--[[
    w =c1c2*c3 - s1s2*s3;
  	x =c1c2*s3 + s1s2*c3;
	y =s1*c2*c3 + c1*s2*s3;
	z =c1*s2*c3 - s1*c2*s3;
	--]]
end

 

[Josh]

The engine already does this. I believe you can just call Quat(Vec3(90,0,0))

[Slastraf]

2 minutes ago, Josh said:

The engine already does this. I believe you can just call Quat(Vec3(90,0,0))

Oh, I thought you needed a W also but it does work like that. This needs to be in the documentation

[Josh]

The Vec3 constructor takes pitch, yaw, and roll and then the quaternion accepts that in the constructor.

[Slastraf]

I have converted the script and tried to make a lot of adjustments, but so far have not been able to accurately replicate rotation of an already working model without bones.

The script is uploaded here, but I don't know why the model with bone (not the green +yellow one) is still acting strangely.
It seems to not track the target blue sphere accurately. 
I have uploaded the bone model before.
Really would like to proceed with normal development speed but I sit on this sole issue for two days now and really don't know any fix.

//edit In the video the model with bone has 3 "parts" of the leg but the rock box should be on the same position as the blue sphere

oldSpiderLeg.lua

[Josh]

You don't actually need to use SetQuaternion in this situation. You could just call SetRotation. You are constructing a quaternion from a Euler with rotation only on one axis, so you aren't going to lose any precision by calling SetRotation with the Euler.

[Slastraf]

1 minute ago, Josh said:

You don't actually need to use SetQuaternion in this situation. You could just call SetRotation. You are constructing a quaternion from a Euler with rotation only on one axis, so you aren't going to lose any precision by calling SetRotation with the Euler.

Yes I have used both now and they have the same result. I thought SetQuaternion was going to fix it but it didn't.

[Josh]

If you can upload the files to run the example I am happy to examine it.

[Slastraf]

6 minutes ago, Josh said:

If you can upload the files to run the example I am happy to examine it.

Yes I hope it was everything.

 

spiderLegFiles.zip

[Slastraf]

Thanks for trying. Is there any fix ? 

[Josh]

I tried extracting your zip archive into a new blank project and running the map but I just get a black screen.

[Slastraf]

Try it in the fps template, it has the fps player in there 

[Josh]

How do I make it run? Nothing is moving.

[Slastraf]

Can you set it up like this ?

[Josh]

If you upload a project that is ready to run I am happy to look at it. I can't guess what your problem is, try to recreate it, and then solve it with any accuracy.

[Josh]

I ran the project and it look like it is running a terrain generation program?

If I run in release I mode I get this error:

index field 'targetPoint' (a nil value)

In spiderleg.lua, line 50, when running the "start" map.