This paper presents a platform aiming the ease of the debate between citizens. In the early 2010’ies, governments are seeking new ways to be more accountable and transparent towards their citizens; marking a renewal in public participation. In return, citizens are eager to be heard and to use new tools based on information and communication technologies (ICT) like the web 2.0. This public’s empowerment presents some costs for the authorities who are mainly concerned with the loss of decision making power. To face those challenges, several 2D online maps have been developed to help the governments to direct and centralize citizens insights. Those previous collaborating mapping tools helped to identify the characteristics of a reliable platform: user-friendly, simple and accessible (anywhere at any time). In our implementation, we adopted the third dimension which provides numerous benefits: 1. A more effective and effortless visualization, 2. An unbiased representation of the environment, 3. The merge of the participant cognition spaces. From our past experiences, we conceptualized the actors (citizens / facilitator / transcriber) interactions and dynamics in public engagement on-site meeting. From this approach, we evaluated how the utilization of a 3D virtual environment as the support of the participation will reshape and enhance the relation synergies between the actors: 1. Centralization of the interactions within the platform, 2. Automated analysis from the gathered raw information, 3. Reachability of a larger part of the population, 4. Lightening of the participatory processes.