Is there a quick way of changing the % Resolution in Output Properties?

Question

I'm always working with big images (> 4K) and very often I use the % Resolution to make quick renders with the original proportion to progressively see the results/issues of the render. Unfortunately, there's no option to add this slider to the Quick Preferences (Q), and I have to adjust this value manually.

Are there other ways to quickly change this value without going to the Output Properties every time?

Answer 1

There is a way to assign this action to a shortcut. Head to the Scripting tab (or open a Text Editor view) and paste this script:

bl_info = {
    "name": "Quick Render",
    "category": "Rendering",
}
import bpy
class QuickRender(bpy.types.Operator):
    bl_idname = "quick.render"
    bl_label  = "Quick render"
    bl_options = {'REGISTER'}
def execute(self, context):
    # setup quick render settings and kick off render
    old_percentage = context.scene.render.resolution_percentage
    context.scene.render.resolution_percentage = 50
    bpy.ops.render.render('INVOKE_DEFAULT')
    # restore old render settings
    context.scene.render.resolution_percentage = old_percentage
    return {'FINISHED'}


addon_keymaps = []
def register():
    bpy.utils.register_class(QuickRender)
    wm = bpy.context.window_manager
    # setup where to run the shortcut
    km = wm.keyconfigs.addon.keymaps.new(name='Object Mode', space_type='EMPTY')
    # setup the shortcut key
    kmi = km.keymap_items.new(QuickRender.bl_idname, 'R', 'PRESS', alt=True)
    addon_keymaps.append(km)
def unregister():
    bpy.utils.unregister_class(QuickRender)
    wm = bpy.context.window_manager
    for km in addon_keymaps:
        wm.keyconfigs.addon.keymaps.remove(km)
    del addon_keymaps[:]
if name == 'main':
    register()

Running the script will enable Alt+R in the 3D view which starts a render with 50% resolution. Look at the comments in the code if you want to change the shortcut details. You can also register the script, so you don't need to run it everytime you open up your project:

I have adopted the code from the Blender addon tutorial. How to setup the shortcut is here and the render call here.