88 lines
2.8 KiB
Markdown
88 lines
2.8 KiB
Markdown
# orx-obj-loader
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Simple loader and saver for Wavefront .obj 3D mesh files.
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##### Usage
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Loading directly into a vertex buffer can be done through `loadOBJasVertexBuffer`.
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```kotlin
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val vertexBuffer = loadOBJasVertexBuffer("data/someObject.obj")
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```
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The loaded vertex buffer can be drawn like this:
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```kotlin
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drawer.vertexBuffer(vertexBuffer, DrawPrimitive.TRIANGLES)
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```
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To save a vertex buffer as an .obj file:
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```kotlin
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vertexBuffer.saveOBJ("my/path/exported.obj")
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```
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<!-- __demos__ -->
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## Demos
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### DemoObjCompoundRW01
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This program loads an OBJ mesh as a CompoundMeshData and demonstrates
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how to convert it to a OBJ String representation, then
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draws the beginning of this String on the program window.
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[source code](src/jvmDemo/kotlin/DemoObjCompoundRW01.kt)
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### DemoObjLoader01
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Demonstrates how to load a `.obj` file as a `VertexBuffer`.
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The `loadOBJasVertexBuffer()` function expects the path to the `.obj` file as an argument.
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[source code](src/jvmDemo/kotlin/DemoObjLoader01.kt)
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### DemoObjSaver01
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Demonstrates how to save a `VertexBuffer` as an `.obj` file using the
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`VertexBuffer.saveOBJ()` method.
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The program loads an existing OBJ file, then saves it with a new file name.
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[source code](src/jvmDemo/kotlin/DemoObjSaver01.kt)
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### DemoObjSaver02
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Demonstrates saving a `VertexBuffer` generated via code as an OBJ file.
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This file can be loaded in a 3D modelling / rendering program.
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[source code](src/jvmDemo/kotlin/DemoObjSaver02.kt)
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### DemoWireframe01
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Demonstrates two approaches for loading an OBJ file: as a `VertexBuffer` and as `CompoundMeshData`.
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A `CompoundMeshData` object contains vertices, texture coordinates, colors, normals, tangents, and bitangents,
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alongside their associated face indices, grouped into meshes.
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In this demo `CompoundMeshData.wireframe()` is called to generate a wireframe representation of the loaded mesh.
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When rendering the wireframe, a shade style is used to displace the lines slightly towards the camera, to ensure
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the lines do not end up occluded by the mesh rendered as triangles.
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Finally, the `sub` method is called on the `Path3D` instances to draw only parts of the wireframe, creating
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an animated effect.
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[source code](src/jvmDemo/kotlin/DemoWireframe01.kt)
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