Contents of 3D SubViewport now look blurry

[lonevox]

Godot version

4.0 beta 2

System information

W10

Issue description

If you have a low resolution Viewport of a 3D scene in 3.5 it looks pixelated, which could be a desired effect like in my project.

3.5:

4.0 beta 2:

This unfortunately seems to be a regression in Godot 4. This might be because of the new SubViewport Scaling 3D feature which can't be found with the old Viewport. Scaling 3D has no option for nearest-neighbor scaling as seen here:

This might not be the reason, I'm just guessing.

Steps to reproduce

Create a SubViewport containing a 3D scene and zoom in on it in the editor. It will look blurred.

Minimal reproduction project

SubViewportScaling3.5.zip
SubViewportScaling4.0beta2.zip

[clayjohn]

What is the texture filter mode set to on the Canvas item using the ViewportTexture? It looks like your CanvasItem is set to use linear filtering (the default) instead of nearest filtering.

Note in 4.0 the texture filter mode is set on the CanvasItem not on the texture itself

[Calinou]

This is not a bug – see @clayjohn's comment above. You can change the default texture filter in the Project Settings (make sure the Advanced toggle is enabled):

You can also set this on the SubViewportContainer to avoid affecting all 2D textures:

See also #60150, #52332 and #57679.

This unfortunately seems to be a regression in Godot 4. This might be because of the new SubViewport Scaling 3D feature which can't be found with the old Viewport. Scaling 3D has no option for nearest-neighbor scaling as seen here:

This is unrelated. 3D scaling only has an impact if the resolution scale is set below 1.0, and it never affects 2D rendering. There are plans to implement a nearest-neighbor scaling option, but not for 4.0 unless a motivated contributor steps up to do the required work.

[lonevox]

Ah apologies. I knew of the texture_filter property but didn't realize it applied to viewports too, but that makes sense. Hopefully this at least helps someone else out if they encounter this when porting.

[prominentdetail]

How do we apply this to a ViewportTexture that is used in a shader? I can't seem to disable the anti-aliasing.

edit: figured it out..

	vec2 screenSize = vec2(textureSize(subView, 0));
	
	ivec2 uvPixel = ivec2( int(UV.x*screenSize.x), int(UV.y*screenSize.y) );
	vec4 c = texelFetch(subView, uvPixel, 0);