Presagis

I’m interested in doing some low level things.

Thanks!

In the future, which document, if any, had this information?

Steve

It depends on how low you will go
Vega Prime provides the ability for you to go directly to the OpenGL layer and handle things yourself. That means the level of OpenGL support is defined by your hardware/driver combination.
That is the lowest level you can go, but allows for pretty much anything you wish to do.

steveo - 18 May 2010 09:01 AM

It depends on how low you will go

Vega Prime provides the ability for you to go directly to the OpenGL layer and handle things yourself. That means the level of OpenGL support is defined by your hardware/driver combination.
That is the lowest level you can go, but allows for pretty much anything you wish to do.

Then Vega Prime doesn’t force us to go through its classes.  So far I have been developing a HUD display using opengl directly with glBegin(...) and glEnd() and various primitives inbetween.  I guess they call this “immediate mode” rendering.  I’m a DirectX graphics programmer primarily so openGL is new territory.  Although most of the concepts are similar.  In DirectX, as a developer, its important to know that support you have (ie. shader model, SDK version, etc.) I need to know this as well for Vega Prime and OpenGL.  I plan to port over some HLSL shader work to Cg (which I believe Vega Prime supports, or at least I know OpenGL does).

Thanks!

vp 3.0.x supports
cg 2.1
opengl 2.x

opengl 3.x coming soon

whitleychas - 14 June 2010 11:42 AM

vp 3.0.x supports
cg 2.1
opengl 2.x

opengl 3.x coming soon

Thanks whitleychas!

I was sort of defaulting to 2.x which (I think) is like Directx 9.x, the more familiar SDK to me.  Knowing it only supports cg 2.1 is also important.

Now, I could just do my own custom rendering in which I can support whatever is installed on the target PC and is supported by the video card.  But I was going to first try and use the “built-in” shader support in Vega Prime 3.x (ie. vrShaderFactory).

Steve

I pretty sure you have to use the VP shader infrastructure. we’re currently experimenting with it ... we’re getting good results.

You would only use the shader infrastructure if you intended to integrate certain shader parts with what is already part of the Vega Prime shader code path. In other words, you would build your functionality into what would otherwise be an automatic shader produced by Vega Prime. That is what the shader infrastructure brings to the table. It allows you to integrate your shader blocks of code with what Vega Prime would already do for you.
Unfortunately, the shader infrastructure isn’t completely productized, so there would be some difficulty in trying that path. The only other option would be to write your own complete shader and attach it to the geometry you are rendering yourself.

My immediate needs are fairly straight forward and simple.  I need a vertex shader to perform billboarding for a particle system we are developing.  Pixel (fragment) shader will come later.  I’ve done something similar in DX and shaders.  Making the user module and lynx prime plug-in is the easy part.  The hard part playing nicely with the existing VP scenegraph and rendering pipeline.  But before we get that deep I would like to make some simple Cg vertex shaders and experiment with the interaction with VP.  The flag waving demo does vertex displacement so I’ll start there.  I have not looked into the supported features of VP’s shader infrastructure yet.

Steve