A method comprising: receiving sensor data representative of surfaces in a physical environment containing an interaction point for a manipulator of a robotic device (100; 300); determining, based on the sensor data, a height map of the surfaces in the physical environment; determining, by inputting the height map and the interaction point into a pre-trained model, a plurality of candidate positions for a mobile base of the robotic device within a region of the physical environment represented by the height map, wherein each respective candidate position of the plurality of candidate positions is predicted by the pre-trained model to allow the manipulator of the robotic device to reach the interaction point when the mobile base of the robotic device is positioned at the respective candidate position; selecting a candidate position from the plurality of candidate positions; determining a collision-free trajectory to be followed by the manipulator of the robotic device to reach the interaction point when the mobile base of the robotic device is positioned at the selected candidate position of the plurality of candidate positions; and based on determining the collision-free trajectory, causing the mobile base of the robotic device to move to the selected candidate position within the physical environment, wherein the pre-trained model was trained by operations comprising: determining a plurality of sample height maps each representing surfaces in a corresponding physical environment that contains therein a respective interaction point for the robotic device; determining, for each of the plurality of sample height maps, one or more validated positions for the mobile base that allow the manipulator to follow at least one collision-free trajectory to the respective interaction point; and determining, based on (i) the plurality of sample height maps, (ii) the one or more validated positions determined for each of the plurality of sample height maps, and (iii) the respective interaction point represented in each of the plurality of sample height maps, the pre-trained model. receiving sensor data representative of surfaces in a physical environment containing an interaction point for a manipulator of a robotic device (100; 300); determining, based on the sensor data, a height map of the surfaces in the physical environment; determining, by inputting the height map and the interaction point into a pre-trained model, a plurality of candidate positions for a mobile base of the robotic device within a region of the physical environment represented by the height map, wherein each respective candidate position of the plurality of candidate positions is predicted by the pre-trained model to allow the manipulator of the robotic device to reach the interaction point when the mobile base of the robotic device is positioned at the respective candidate position; selecting a candidate position from the plurality of candidate positions; determining a collision-free trajectory to be followed by the manipulator of the robotic device to reach the interaction point when the mobile base of the robotic device is positioned at the selected candidate position of the plurality of candidate positions; and based on determining the collision-free trajectory, causing the mobile base of the robotic device to move to the selected candidate position within the physical environment, wherein the pre-trained model was trained by operations comprising: determining a plurality of sample height maps each representing surfaces in a corresponding physical environment that contains therein a respective interaction point for the robotic device; determining, for each of the plurality of sample height maps, one or more validated positions for the mobile base that allow the manipulator to follow at least one collision-free trajectory to the respective interaction point; and determining, based on (i) the plurality of sample height maps, (ii) the one or more validated positions determined for each of the plurality of sample height maps, and (iii) the respective interaction point represented in each of the plurality of sample height maps, the pre-trained model. determining a plurality of sample height maps each representing surfaces in a corresponding physical environment that contains therein a respective interaction point for the robotic device; determining, for each of the plurality of sample height maps, one or more validated positions for the mobile base that allow the manipulator to follow at least one collision-free trajectory to the respective interaction point; and determining, based on (i) the plurality of sample height maps, (ii) the one or more validated positions determined for each of the plurality of sample height maps, and (iii) the respective interaction point represented in each of the plurality of sample height maps, the pre-trained model.