Demo application?

[bjorn-ali-goransson]

Hello there,

I'm curious how you visualize the results of the SharpGLTF logic yourself, do you happen to have a OpenGL example application that shows the loaded GLTF?

Maybe this is wishing too much.

Context, I'm currently trying to make OpenRA into a Lego Game (TellTale) engine, and it's time to load assets and I discovered GLTF. It's right over here: https://github.com/bjorn-ali-goransson/TellMeAStoryEngine

[vpenades]

Not sure if I understand your question.

If you want a program that displays glTF files, windows itself comes with an in built 3D model viewer that is able to open and display glTF models.

If what you want is a demo on how to render a glTF to screen, I've done some basic stuff using MonoGame engine, but it's far from a good example due to the limitations of MonoGame, which makes the code extremely ugly.

In the end, SharpGLTF is just a loader/authoring library, and rendering is out of scope because it would require writing code for every single rendering API.

But, regardless of the rendering API, there's some boilerplate code that should be common to all rendering APIs, like evaluating the nodes, calculating matrices, etc.... you can find that code in the runtime namespace. It's not documented though, so you'll have to navigate around it yourself.

[bjorn-ali-goransson]

Understood, thank you! Yes I began to traverse the nodes / indices 👍🏼 .

I just saw that the glTF format includes strides and a "buffer" so I thought maybe there is some easy way to transfer this onto a buffer object, but no worries.

[vpenades]

buffer strides is just one detail among one hundredth. It took me a month of work to write the renderer for MonoGame, so it's not a simple task.

glTF rendering can be divided in two main sections:

• Stuff that is engine specific and needs to be uploaded to the GPU: vertex/index buffers, textures, material states, etc.
• Stuff that describes how/where/when the former resources needs to be rendered.

The gpu resources need to be converted from glTF to your engine of choice using your own code, and there's little the library can do about it.

For the scene description stuff, there's the Runtime namespace that has several utilities that simplify the work: I would begin looking at SceneTemplate and SceneInstance classes.

[bjorn-ali-goransson]

Much appreciated sir. Thanks!