Found a Corona Scatter object that uses more than one unique map plugged into its scale map slots. This setup cannot be automatically converted to the current Scatter version. Please, select the object and adjust it manually according to the linked help page.
This message appears only if:
- There is at least one Corona Scatter in your scene set up with more than one unique map controlling the scaling of the scattered instances
- Your scene was created in Corona 3 or older and you are opening it with Corona 4 or newer
OR - You are opening your scene in Corona 8 or newer where Chaos Scatter replaces the legacy Corona Scatter
This is because the way how scale is controlled in Corona Scatter has changed in Corona 4 (and in turn Chaos Scatter in Corona 8 and newer), and since it is not possible to achieve the same results automatically, you will have to adjust the way your textures are loaded.
Note: scenes in which scaling of Corona Scatter is not controlled by textures, or is controlled by just one texture plugged into one slot or where it is controlled by one map plugged into multiple slots, will render exactly the same in Corona 3 and 4 and in such cases there is no need for manual updating or any other extra steps!
How to get the same results in Corona 4 or newer as in older versions?
Here is an example:
Note: this guide was originally created for Corona 3 and 4, where the legacy Corona Scatter was used, however the below instructions can be used to achieve the expected results also in Corona 8 and newer with the new Chaos Scatter (the UI of Chaos Scatter is different overall, but very similar in the parts mentioned in this guide).
We have a scene created with Corona 3, with Corona Scatter set up with 3 different textures controlling the scaling of the scattered objects in 3 different axes:
This is what it looks like when rendered with Corona 3:
Now, let's open this same scene in Corona 4 or newer. You will see that:
- This warning message pops up
- The scatter looks different than in Corona 3
- The Scale map slot is empty
This is because in Corona 3 we were using 3 different maps for controlling the scale. In Corona 4 and newer we can only use one map for this. The scale in each axis is now controlled by RGB values of the scale map.
So how to fix this?
Since in Corona 4 and newer the scaling axes are controlled by RGB values of the scale map, we will have to combine the 3 maps that we are using into one. We will use RGB Multiply and Composite nodes for this:
1. Create an RGB Multiply node in the material editor, and duplicate it 2 times to get a total of 3 nodes.
2. Plug each of your scale maps into each of the RGB Multiply nodes' "Color 1" slots.
3. The RGB Multiply nodes now need to be set up:
For the first RGB Multiply node (used to control the X scaling axis), set its "Color 2" to pure red (RGB: 255,0,0).
For the second RGB Multiply node (used to control the Y scaling axis), set its "Color 2" to pure green (RGB: 0,255,0).
For the third RGB Multiply node (used to control the Z scaling axis), set its "Color 2" to pure blue (RGB: 0,0,255)
4. Create a new Composite node, and add two extra layers in it, to have a total of 3 layers. Use the "Add A New Layer" button for this.
5. Plug your RGB Multiply nodes as Layer 1, Layer 2, and Layer 3 of the Composite node.
6. In the Composite node's options, change each layer's blending mode to "Addition".
7. Plug the resulting Composite map into the Corona Scatter's Map slot.
8. Make sure that Mode is set to "Legacy".
9. Make sure that Adequate checkboxes controlling which axis the map is applied to are ticked. The checkboxes should be ticked only for those axes which are controlled by the map. For example, if the Z axis was not controlled by a map in Corona 3 or older (the Z scale slot was empty), then the Z checkbox should be left un-ticked under "Map:" in Corona 4 or newer.
If you have followed the above steps correctly, the result of Corona 4 or newer rendering will be exactly the same as the original result of the Corona 3 rendering:
Related article: How to use Scale Map in Corona Scatter?