One easy way to work around this problem is to keep a second matrix around that will store all of the accumulated rotations. If you rotate left and right from a point of zero rotation, the cube will rotate as you expect, but what if you then rotate it up or down 180 degrees? Trying to rotate the cube left or right will now rotate it in the opposite direction! The main problem with the simple way of rotating is that the object is being rotated in relation to itself, instead of in relation to the user’s point of view.
#HOW TO IMPORT BLENDER TO JAVA LWJGL HOW TO#
How to make the rotation appear relative to the user’s point of view. We could also rotate an object around the Z axis if we wanted it to spin around. To rotate an object up or down, we rotate it around the X-axis, and to rotate an object left or right, we rotate it around the Y axis. Here is example pseudocode: tIdentity(modelMatrix)
![how to import blender to java lwjgl how to import blender to java lwjgl](https://i.ytimg.com/vi/aPRBbJ7WtiU/maxresdefault.jpg)
This is the easiest way to rotate an object based on touch movement. In this article, I’ll take a look at a simple way to rotate an object based on the touch events, and how to work around the main drawback of this method. Its still a question if the Blender GLTF2 animation importer is usable enough.Īll in all, the animated model import/export situation does not look too good around Java.Rotating an object in 3D is a neat way of letting your users interact with the scene, but the math can be tricky to get right. The existing Java GLTF2 importer/exporter does not look optimal, but would be a good starting point. The format is pretty readable and open, much simpler than FBX in structure. The drawback here that its another binary library, so if there is some error, it will crash the JVM. Blender can read/write FBX files not perfect but good enough, so this could work, when Blender-specific stuff/bugs are also considered. Only the FBX SDK can read/write FBX files perfectly. I see two possibilities to have animated model import/export based on a modern format:ġ. Its a petty that Assimp supports so many formats, but can't export animations with either of the formats. There is a patched Blender PSK/PSA importer source available from GitHub, and its possible to write a matching exporter for that in Java. So in the end i had to resolve to my own PSK/PSA exporter/importer to get animated models and animations into Blender and from Blender. Sometimes the file with animation is written, but it is wrong in Blender. The armature imports perfectly into Blender.īut trying to export the animation, even if empty, will either return with an error code, or crash the JVM, in the destructor of AIScene.
![how to import blender to java lwjgl how to import blender to java lwjgl](https://i.stack.imgur.com/LEGsT.png)
The best result to export an armature to Blender with Assimp is by using GLTF2 exporter.
![how to import blender to java lwjgl how to import blender to java lwjgl](https://i.stack.imgur.com/6SZ4X.png)
So practically the whole export process completes, but crashes at releasing the scene. Its a C++ exception, somewhere in the destructor of the AIScene class. The armature exported wtih Assimp Collada exporter imports wrong into Blender.Įxporting animation with Assimp crashes the JVM. The FBX model (even just static model, no armature) exported from Assimp can't be opened in Maya or MAX, but Blender handles it. The Blender 2.79 FBX importer is not the best either, but it opens the model, with matching armature, but rotated bones. The armature can be exported with FBX and it imports ok into Blender, but not the animation. I looked at the Assimp github source, and this is missing, its not documented anywhere either. This post can serve as a kind of a warning to other people if they try to use Assimp for exporting models.Īnimations are not implemented in the Assimp FBX exporter.
![how to import blender to java lwjgl how to import blender to java lwjgl](https://koenig-media.raywenderlich.com/uploads/2013/08/g_OBJ.png)
I spent now a lot of time trying to import and export animated models and animations with Assimp, unsuccessfully. This might not be an LWJGL issue or bug, but generally Assimp related.