"bug" in tutorial, what is the issue?

Questions
1

Hello,

Firstly I am *not complaining about the tutorials - they are great !
For tutorial #3, when you pick a planet up, it gets a little bigger, and then when you drop it, it returns to normal size.
However *sometimes it does not return to normal size, and stays enlarged.
You can even see it happen at the start of the video !

I’ll attach a project.

I’m confused about why this happens, looking at the code it seems ok ?
Any thoughts ?

Hmm I can’t attach a project ?
I downloaded them from here:
https://drive.google.com/drive/folders/1XOQbzHt0Mg0fxAvYBN1ysNCPbxKvgImQ
(hope it’s ok to share links)

I’m planning to leave (positive!) feedback at www.tactxstudios.com also

2

I haven’t looked at the code but you mentioned that it gets bigger. Is it an animation? It could be that the animation gets cancelled before completed?

3

There is a cursor.script that has this bit

	-- Revise script control variables; click/touch -- as pressed or released 
	if action.pressed then
		-- When the action reflects a press
		msg.post("#collisionobject", "enable")
		self.pressed = true

	elseif action.released then
		-- When the action reflects a release
		msg.post("#collisionobject", "disable")
		self.pressed = false
		self.dragged_id = nil
		self.dragging = false

		-- Reset the scale to 1.0 on Selected GameObject when released
		local s1 = vmath.vector3(1.0, 1.0, 1.0)
		go.set_scale(s1, self.collision_id)
	end

So it looks like the scale command gets missed somehow ?

4

Ok, so there is code to reset the scale. But I’m guessing the scale gets changed somewhere else?

5

Since the only thing affecting the scale of any nodes within the provided script is the set scale, so I imagine that either the nodes are set to scales of less than vmath.vector3(1.0, 1.0, 1.0) in the relevant collection or that there is code elsewhere that also alters the scale. If you could send me your project file, I could find the problem and give you a fix :slight_smile:

6

Sent via discord (I’m not sure this is the best way to send it ?)

1 Like
7

Here is the entire script, the scale is changed in two places looks like:

function on_input(self, action_id, action)

-- Only process inputs which reflect a 'touch action' as defined within game.input_bindings
if not action_id or action_id == hash("touch") then

	-- Update the Defold cursor Game Object position to be the same as the current 
	-- position of the machine cursor
	local action_pos = vmath.vector3(action.x, action.y, 0)
	go.set_position(action_pos)

	-- Revise script control variables; click/touch -- as pressed or released 
	if action.pressed then
		-- When the action reflects a press
		msg.post("#collisionobject", "enable")
		self.pressed = true

	elseif action.released then
		-- When the action reflects a release
		msg.post("#collisionobject", "disable")
		self.pressed = false
		self.dragged_id = nil
		self.dragging = false

		-- Reset the scale to 1.0 on Selected GameObject when released
		local s1 = vmath.vector3(1.0, 1.0, 1.0)
		go.set_scale(s1, self.collision_id)
	end

	-- Upon a Click/Touch -- if the cursor has collided with another GameObject and
	-- is not already dragging another GameObject -- then set dragged_id / dragged_pos
	-- to the new GameObject's id

	if self.pressed and self.collision_id and not self.dragged_id then
		self.dragged_id = self.collision_id
		self.dragged_pos = action_pos

		-- Increase Scale for selected GameObject when selected
		local s2 = vmath.vector3(1.2, 1.2, 1.0)
		go.set_scale(s2, self.collision_id)
	end

	-- Set self.dragging to true if user has clicked a GameObject and moves it
	if self.dragged_id and vmath.length(self.dragged_pos - action_pos) > 20 then
		self.dragging = true
	end

	-- Update the position of a dragged GameObject
	if self.dragging then
		go.set_position(action_pos, self.dragged_id)
	end
end

end

8

Solved,

Solution:

elseif action.released then
	-- When the action reflects a release
	msg.post("#collisionobject", "disable")
	self.pressed = false
	self.dragging = false

	-- Reset the scale to 1.0 on Selected GameObject when released
	local s1 = vmath.vector3(1.0, 1.0, 1.0)
	go.set_scale(s1, self.dragged_id)
	self.dragged_id = nil
end

the alterations are: move self.dragged_id = nil to below go.set_scale and modify the second parameter of go.set_scale to “self.dragged_id”

This bug occurred because the previous code was, when the mouse was released, altering whatever game object collided first, which in this case would always be the one on top. This fix solves this problem by storing and referencing a specific game object id, and taking the collision out of the action.released

grify
:heart:

1 Like
9

I probably should have posted the whole script in the first place :slight_smile:

Here is a diff

old

		elseif action.released then
			-- When the action reflects a release
			msg.post("#collisionobject", "disable")
			self.pressed = false
			self.dragged_id = nil
			self.dragging = false

			-- Reset the scale to 1.0 on Selected GameObject when released
			local s1 = vmath.vector3(1.0, 1.0, 1.0)
			go.set_scale(s1, self.collision_id)
		end

new

        elseif action.released then
            -- When the action reflects a release
            msg.post("#collisionobject", "disable")
            self.pressed = false
            self.dragging = false

            -- Reset the scale to 1.0 on Selected GameObject when released
            local s1 = vmath.vector3(1.0, 1.0, 1.0)
            go.set_scale(s1, self.dragged_id)
            self.dragged_id = nil
        end

Thanks everyone !

1 Like
11

I sort of wonder now whether that’s intentionally part of the tutorial :wink: