Load Model in xNa

Generally, for a 3D presentation system, the models are completed in advance in software such as 3dmax, and then loaded to the system for presentation. XNa supports many formats of models, but it is connected to fbx files with 3dmax.

The underlying d3d of xNa, so the rendering essence of the model is also d3d rendering. In the new d3d version, similar to the C-language moral GPU language has emerged. Of course, this is mainly due to the development of graphics technology.

Currently, there are three main GPU languages: glsl for OpenGL, CG for NVIDIA, and HLSL for Microsoft Based on d3d. Among them, CG and HLSL are a product of NVIDIA's cooperation with Microsoft, but finally, for some reason, they part ways. NVIDIA is CG and Microsoft is HLSL, but their usage and syntax are similar.CodeCan run.

If we use xNa, it is better to support HLSL like other Microsoft technologies. I haven't found an example of xNa supporting GC. I don't think so. Because I have read an articleArticleComparing these three GPU languages, he said that he has no reason not to use GC. CG supports OpenGL and d3d at the same time. Since GC is so good, all the xNa code I have read uses HLSL, which may indicate that xNa does not support GC.

The essence of d3d rendering is to select and render the triangle planes one by one. More and more triangle planes constitute the triangle,CubeBody, cylinder, sphere, and more complex terrain, trees, people, animals, etc. The final rendering code is the GPU code, and then some effects such as illumination and texture are made when these triangles are selected, finally presenting a vivid 3D scene.

XNa provides the model class and common 3D rendering class. The 3D rendering class encapsulates GPU Code, allowing developers to quickly and conveniently render models rather than write GPU code. However, xNa provides limited functions. If you want to achieve refraction, reflection, and highlight effects, you need to write GPU Code independently.

Next, let's take a look at the definition in xNa.

The Code is as follows:

Model mymodel = This . Content. Load <model> ( @"  Content/models/Tank  " );
 Foreach (Modelmesh mymesh In Mymodel. Meshes)
{
Matrix myworld = mymesh. parentbone. Transform * matrix. createscale ( 0.01f );
 Foreach (Modelmeshpart mymodelmeshpart In Mymesh. meshparts)
{
Basiceffect mybasiceffect = mymodelmeshpart. Effect As Basiceffect;
Mybasiceffect. World = myworld;
Mybasiceffect. view = This . Activesence. Camera. view;
Mybasiceffect. Projection = This . Activesence. Camera. projection;
Mybasiceffect. textureenabled = True ;
Mybasiceffect. currenttechnique. Passes [ 0 ]. Apply ();
 This . Graphicsdevice. Indices = mymodelmeshpart. indexbuffer;
 This . Graphicsdevice. setvertexbuffer (mymodelmeshpart. vertexbuffer );
 This . Graphicsdevice. drawindexedprimitives (primitivetype. trianglelist
, Mymodelmeshpart. vertexoffset, 0 , Mymodelmeshpart. numvertices
, Mymodelmeshpart. startindex, mymodelmeshpart. primitivecount );
}
}

 

Here, model is the class defined for the model in xNa. Basiceffect is a rendering class customized by xNa. It encapsulates General GPU rendering.

The running effect is as follows: