USE CORONA SCATTER to ADD CARS to A SCENE
01The PREPARE Our VEHICLE models
first step is to prepare the car model we will scatter. I set the correct maps for the model, then I made the model one single polygon by attaching all its parts (remember to select Match Material to Material IDS). It might take a while attaching. Once it’s done it might be a good idea to save in a private attached car model collection so that you can use it in another project without having to attach again.
Now it’s time to convert the model from V-ray to Corona. I'm using Corona Converter v1.39. Select Materials of selected objects, and click Start Conversion. In the video I show which options I select, but the most important I would say is Disable Displacement Maps. Finally check the pivot so that it can be in the centre of the car and at its bottom. Now we can proceed.
02 Create Our traffic guides
Now it’s time to add our guides so that our models can be spread where we want them to be. I will use Corona Scatter to scatter our models along splines. In this case what I did is simple – I started adding lines from one side of the street, then I did more on the other side and finally I added four more in the main street. These are our guides, and all we are going to scatter will go right here. In this case I used only straight lines, but you can also add curves and the models will adapt to them too. Always remember to have the splines close to the ground.
03 Scatter Cars in the Street
Now it’s time to set our Corona Scatter, and once it’s in our scene we need to tweak some of the options. In the Scattering rollout select 1D On Splines. This will enable us to scatter our models along the spline. In Instanced Objects add our car model and in Distribute on Objects we will select our line guides. Now we have the car model scattered in the line.
Next in the Transformations tab, in Rotation set z: 90° so we can have the models facing the right way, and now in Viewport Display set the % displayed to 100, so we can see all the models we have in our scene. Finally in Avoid Collisions enable spacing to 100%, this way the models won’t appear overlapped. Now we have the area filled with cars. Next it’s time for some final settings tweaks for producing our desired result.
04 Final Settings
Now we need to make the cars appear lifelike. First in Spline Scattering we will change the spacing. I find that playing with the values gives a lot more options, and in this case I experimented with the Spacing and the Translation values from the Transformation tab. In this case I set Spacing to 6 and Translation to 65. I pressed Render and really liked the result. Now we have a nice traffic scene using only one model.
Select the car and add it as an exception from the override. Now we have one car, but at the moment everything is the same, so it’s time to make it look like there is more than one model of car. Select the car model and in Slate Material bring their materials up, find the Carpaint material and then add a Corona Multimap. Set it as instance and now every car has a different colour. You can choose the number of maps to use in Multimap. And this is the method I use to add traffic to my render. Hope you like it!