When a specified source is shown, the specifed scene will appear within the specied duration.

auto_transaction.lua

obs = obslua
showing_slide = false
slide_name_from = ""
slide_name_to = ""
duration_ms = 1000000

function scene_active_from_name(name)
    local sceneSources = obs.obs_enum_sources()
    local ret = false
    for _, sceneSource in ipairs(sceneSources) do
        local active = obs.obs_source_active(sceneSource)
        local scene_name = obs.obs_source_get_name(sceneSource)
        if active and scene_name == name then
            ret = true
            break
        end
	end
    obs.source_list_release(sceneSources)
    return ret
end

function find_source_by_name_in_list(source_list, name)
    for i, source in pairs(source_list) do
      local source_name = obs.obs_source_get_name(source)
      if source_name == name then
        return source
      end
    end
    return nil
  end

function activate_scene(switch_scene_name)
    local scenes = obs.obs_frontend_get_scenes()
    local switch_scene = find_source_by_name_in_list(scenes, switch_scene_name)

    if switch_scene ~= nil then
        obs.obs_frontend_set_current_scene(switch_scene)
    end
    obs.source_list_release(scenes)
end

function transition_timer_tick()
    obs.remove_current_callback()
    if not scene_active_from_name(slide_name_from) then
        return
    end
    
    activate_scene(slide_name_to)
end

function source_activated(cd)
    local source = obs.calldata_source(cd, "source")
    if source == nil then
        return
    end

    if obs.obs_source_get_type(source) ~= obs.OBS_SOURCE_TYPE_INPUT then
        return
    end

    if obs.obs_source_get_name(source) == slide_name_from then
        obs.timer_add(transition_timer_tick, duration_ms)
    end
end

function script_properties()
    local props = obs.obs_properties_create()
    local scenechoice_from = obs.obs_properties_add_list(props, "scenechoice", "Switch from scene", obs.OBS_COMBO_TYPE_EDITABLE, obs.OBS_COMBO_FORMAT_STRING)
    obs.obs_property_list_add_string(scenechoice_from, CURRENT_SCENE_OPTION, CURRENT_SCENE_OPTION)
    local scenechoice_to = obs.obs_properties_add_list(props, "scenechoice2", "Switch to scene", obs.OBS_COMBO_TYPE_EDITABLE, obs.OBS_COMBO_FORMAT_STRING)
    obs.obs_property_list_add_string(scenechoice_to, CURRENT_SCENE_OPTION, CURRENT_SCENE_OPTION)

    local sceneSources = obs.obs_frontend_get_scenes()
    for _, sceneSource in ipairs(sceneSources) do
		local name = obs.obs_source_get_name(sceneSource)
		obs.obs_property_list_add_string(scenechoice_to, name, name)
	end
    obs.source_list_release(sceneSources)
    
    local sources = obs.obs_enum_sources()
	if sources ~= nil then
		for _, source in ipairs(sources) do
            local name = obs.obs_source_get_name(source)
            obs.obs_property_list_add_string(scenechoice_from, name, name)
		end
	end
	obs.source_list_release(sources)


	obs.obs_properties_add_int(props, "duration", "Duration (ms)", 1, 1000000, 1)
    return props
end

function script_description()
    return "Sutomatic scene transition."
end

function script_load(settings)
    local sh = obs.obs_get_signal_handler()
	obs.signal_handler_connect(sh, "source_activate", source_activated)
end

function script_update(settings)
    slide_name_from = obs.obs_data_get_string(settings,"scenechoice")
    slide_name_to = obs.obs_data_get_string(settings,"scenechoice2")
	duration_ms = obs.obs_data_get_int(settings,"duration")
end