1. Before We Start
Now before we begin we will need to install a couple things:First, we need a 3D modeling program, I will be using Blender 2.79 in this tutorial.
Secondly, we need The Switch toolbox, this makes importing 3D models into Mario kart 8 possible
(Optional) Third we need two blender plugins: these are “CATS” and Material combiner, on each of the download pages there will be a short tutorial on how to install blender plugins.
Finally we need a model, here is a link to the Model Resource
Before we start I need to mention some prerequisites:
First off, your texture file size will need to be equal or less than, than the one you are replacing, to check the file size of your characters textures simply drag and drop your characters file into the switch tool box, character files can be found in content/driver, once it Is opened click the BFRES file and then textures.
Most characters have 512 x 512 textures for the body and 256 x 256 textures for the eyes/mouth however some don’t such as Donkey Kong who has 1024 x 1024 textures.
Second make sure that your vertices/polygons are less than 6000, you can go over however the game will lag.
2. Let's Start
Ok lets begin! Import your model into blender, if your model is not rigged please goIf your non-rigged model has multiple textures you will need to atlas them before we put It in a auto-rigger.
2.1. Mixamo Auto-rigging Method
For this tutorial we will put this model into an auto rigger called Mixamo, signing up for this website is completely free.
Click Upload character, now just drag and drop your 3D model file into mixamo.
Adjust the model with the buttons if you have to, now put the markers over the model like the diagram shown, under skeleton LOD mark it as 2 chain fingers, Mario kart 8 uses 4 bones to control the fingers, we can merge child bones’ weights when we get into blender, after this click next, the auto-rigging process may take some time so please be patient
When it is done you will get a preview of your character, if you are happy with the results click next.
This is optional but you can select the animations and do some extra proofing. When you are finally done click download, when it asks you what format you want to export as, go under format and pick .DAE, this 3D model format the most universal.
Once you have your model imported the materials may be deleted, lets fix this! Create a new material in the material tab and scroll down to MMD texture and select the characters texture, once done click Fix model in the CATS tab.
3. In Blender
When you import your model and if you haven’t already, click Fix model in the CATS tab. After this go to vertex groups and go into Weight paint mode and check the weight painting. Please refer to your characters skeleton. Also merge any bones to the parent by selecting them in edit mode and clicking merge to parents in the CATS tab.Sometimes when you import your model the textures maybe broken, to fix this go to MMD texture in the material tab and select the right textures, also you may need to delete any materials you don’t need.
If you have any bones that are missing such as here with the head this might mean that CATS has deleted it, not to worry we can easily fix this! First go to edit mode and then select the end of the parent bone and press E, this will add a child bone, now simply rename this to the original name of the bone, this name can be found in Vertex group, when you do this it will transfer all the weights to the new bone, repeat this if some more bones have been deleted. To parent bones, right click all the bones and select the LAST one to be the parent then to Ctrl + P then click Keep Offset.
Also I recommend that you pose your model in a correct stance aka a T-pose.
Now we are going to rename all the bones to what your character uses, again refer to the skeleton list.
If you want to make a shadow map I would recommend THIS tutorial made by the creator of “The Switch Toolbox” KillzXGaming.
3.1. Texture Atlas
We are almost finished in Blender! The last thing we need to do is atlas the textures, remember, Mario kart 8 characters use 1 object and 2 materials, this being the body and the eyes/mouth, if you have textures like this Lucario example I have here, you will need to atlas them, however if you have only two textures you can ignore this step.First go the Material combiner tab and tick/untick the textures you need to combine, for the atlas size I recommend Quadratic with “Size of gaps between images” set to zero.
Now before you create your atlas, save your blender scene just in case something brakes. Now click “Save atlas to..” and select the folder location of your atlas. When you do this you may have a weird lighting issue, this is probably a bug with the material combiner, we can very easily fix this!
Open a photo editing program, you can use any, however I recommend paint.net since it’s free and easy to use. Open your atlas and overlay your original textures over the atlas, once you do this, save the image.
Before we export, make sure your materials are renamed to “Body__m_Body” for the body, and “Body__m_Eye” for the eye/mouth.
3.2. Exporting
Lastly we need to export! I recommend using the CATS plugin for exporting but you can use blenders built in exporter, make sure the file you export is either a .DAE or .FBX file.Ok now we are finished in blender!
Alright lets get this model imported in-game!
3.3. Getting it in-game
First drag and drop your character file into “The Switch Toolbox”.
This extra step will be important later, go into settings, a window will now pop up, the check boxes are self explanatory.
Now, let’s finally import our model! Go into models and right click your character and select replace, select your exported model, you should now see this menu, make sure all these settings are like shown on screen, after clicking OK, uncheck “Use material” and “Create Placeholder Textures”, next click the “inject mode” tab, check all these options, now click on the “Current” materials and rename them to the appropriate names on the right, once you are finished click on the model settings tab and click save.
You should now have your model imported in, but we are not finished yet! Right click your character and select “transform”, if your model is too small then I recommend setting the scales to 1.1, set them all to 1.01 for more precise sizing, if your model is too big then set all the scales to 0.5.
You want to try and position your model to align the armature.
Ok lets test this! Go to animations, then Skeletal animations and click on any animation to see what your model will look like when put in-game. Hmmm, it seems that the animations look broken, lets fix this! I would start by sizing the model up and then repositioning the bones, to reposition the bones, go to your character and then skeleton, start by collapsing all the bones until you have reached the bones that need to be re-positioned, I don’t recommend stretching out the bones too much as it may brake other animations.
Now lets apply our textures, under the textures section right click the textures that end with _Alb and click replace, do this for all your model textures, also replace the pupil texture with a transparent image.
If you don’t want to include a spectral map, set all the textures that end in SPM to a 1x1 black image
When you have done all this you are done! Simply click save/save as and click yes when it asks you to compress with Yaz0.
Congratulations!
You have now imported a model into Mario kart 8!
