Resize with no stretch/shrink of Window's 3D Contents

MrNybbles

I've been unable to find anything online relating to the answer I'm looking for. All the key words keep taking me to solutions to other problems.

Basically the Camera class has a Property called keep_aspect which must be set to either KEEP_WIDTH or KEEP_HEIGHT. One will cause the 3D contents of the window to only stretch/shrink when resizing vertically and the other will cause the contents to stretch/shrink when resizing horizontally.

Problem: There is no option to prevent stretching/shrinking when resizing in either direction.

I've also tried every combination of settings from the menu Project => Project Settings... -> Display -> Window :> Stretch >> Mode and Aspect.

The closest work-a-round I have figured out is this:


extends Spatial

onready var viewport : Viewport = get_tree().root


func _ready() -> void:
	assert(OK == viewport.connect("size_changed", self, "_on_resize"))


func _on_resize() -> void:
	var val : float = 1.0 - ((1280.0 - OS.window_size.x) / 1280.0) # This almost works, almost. . .
	viewport.get_camera().fov = 70.0 * val

Notes: Camera.keep_aspect = KEEP_WIDTH 1280.0 is my initial Window width. 70.0 is my initial Camera.fov.

Drop the above GDScript code into a script attached to a node in the scene and it Should Just Work™ (just not 100% correctly).

Defect: When the window gets small enough, val grows a little too big and ends up zooming in instead of keeping the contents of the window the same size.

I don't know how to work out the math correctly to get it to work. Basically Camera.fov is not a linear value.

Is there a better solution, has this been solved somewhere else that I haven't found, or can someone please help me out with the math one?

Binsk

Hm... surprised there isn't a built-in way to do this via settings. Well, I messed around for a bit and figured out that you can do it with a viewport container and a viewport, the container being the important part. If you place everything inside this new viewport then it seems to work pretty flawlessly.

So, what I did. I created a viewport container and set it's anchor points to anchor it to the center of the screen, size of 0x0. I dropped a viewport inside of this thing and set its size to what I wanted. This was 640x480 for testing purposes.

Keeping the viewport container's anchors in tact, I moved its position off-center by half the size of the viewport so that the viewport would render center of the screen. So -320x-240 of whatever the center point of the screen is.

Place your game inside that viewport and you're good to go. It will always remain whatever size you specified the viewport to be.

MrNybbles

Thank you Binsk, your solution fixes the issue!

The only side-effect is because the ViewportContainer is a Control, it eats the input handled by my unhandled_input() function. I just renamed it input() and it works again.

I'd mark your answer as the Accepted Answer, but i just realized I posted this as a New Discussion instead of as Ask a Question.

EDIT: While this solved the issue with the contents getting squished when the window was made smaller, when the window's size was made bigger than the size of the Viewport* the contents would begin to be scaled larger.

Only in one direction top/bottom or left/right depending on if Camera.keep_aspect was set to Camera.KEEP_HEIGHT or Camera.KEEP_WIDTH.

How I dealt with this: 1) Set the ViewportContainer's anchor points to Full Rect. 2) Set the ViewportContainer's Grow directions both to BOTH. 3) Set Camera.keep_aspect = Camera.KEEP_HEIGHT (which allows resizing left/right as much as I want with no unwanted shrink/stretch). 4) Set the initial Window Height to 1080 in Project Settings. However, if resized larger than 1080 the contents will get larger. 5) Used the following GDScript in ViewportContainer.

extends ViewportContainer

onready var viewport : Viewport = $Viewport


func _ready() -> void:
	viewport.size = OS.window_size
	assert(OK == connect("resized", self, "_on_resize"))


func _on_resize() -> void:
	viewport.size = OS.window_size

Note: 1) Without filling the 3D screen with content it is very easy to miss when the inner Viewport is being clipped. 2) The viewport.size = OS.window_size code keeps the Viewport contents filling the entire Window, even when the Window is bigger than the viewport.

Binsk

Maybe I'm misunderstanding something. You didn't want the viewport to change size at all, correct? Always stay the same size and thus pad the edges if the window is resized? This seems to work for me, no code required:

upsetbabygames.com/static/freedownloads/3D%20Viewport%20Example.zip

Either way, it sounds like you might have figured it out so awesome sauce there.

TwistedTwigleg

@MrNybbles said: I'd mark your answer as the Accepted Answer, but i just realized I posted this as a New Discussion instead of as Ask a Question.

I changed the topic from a discussion to a question for you and marked @Binsk's post as an answer :smile:

MrNybbles

@Binsk said: Maybe I'm misunderstanding something. You didn't want the viewport to change size at all, correct? Always stay the same size and thus pad the edges if the window is resized? This seems to work for me, no code required:

upsetbabygames.com/static/freedownloads/3D%20Viewport%20Example.zip

Either way, it sounds like you might have figured it out so awesome sauce there.

It's not the viewport I wanted to keep the same size, it is the contents (the 3D meshes rendered within) I wanted to keep the same size.

I now see that the word contents can be interpreted to mean what is drawn within the window as well as what nodes are nested within the Window. This is why I was originally using the Camera.fov (which basically zooms in or out the camera) to scale the contents back to their original size, I just didn't know mathematically how to calculate the proper scale. EDIT: Added images showing Normal-sized window (Bottom Image), the unwanted vertical squish of contents when the window is resized (Top Image), and what it should look like when the window is resized with the contents still the same size as the original (Middle Image). Basically I don't want squished contents when resizing BOTH vertically or horizontally instead of having to pick one or the other.