logo标签列表

在XNA 4.0中绘制具有多个面的纹理立方体

c#xna
7

我已经为这个问题苦苦思索了好几个小时。我的目标是绘制一个立方体，每个面都有不同的纹理；更具体地说，我想能够针对每个面指定任何纹理。我使用这里的示例开始，然后尝试进一步开发它，以便我可以拥有多个纹理。然而，无论我做什么，它仍然只使用应用于效果的最后一个纹理，并且不考虑任何先前的赋值。这是我的形状类：

public class BasicShape {

 public Vector3 shapeSize;
 public Vector3 shapePosition;
 private VertexPositionNormalTexture[][] shapeVertices;
 private int shapeTriangles;
 private VertexBuffer shapeBuffer;
 public Texture2D topTexture;
 public Texture2D frontTexture;
 public Texture2D backTexture;
 public Texture2D leftTexture;
 public Texture2D rightTexture;
 public Texture2D bottomTexture;

 public BasicShape(Vector3 size, Vector3 position) {
    shapeSize = size;
    shapePosition = position;
 }

 private void BuildShape() {
    shapeTriangles = 12;

    shapeVertices = new VertexPositionNormalTexture[6][];
    for(int i = 0; i < 6; i++) {
        shapeVertices[i] = new VertexPositionNormalTexture[6];
    }

    Vector3 topLeftFront = shapePosition +
     new Vector3(0.0f, 1.0f, 0.0f) * shapeSize;
    Vector3 bottomLeftFront = shapePosition +
     new Vector3(0.0f, 0.0f, 0.0f) * shapeSize;
    Vector3 topRightFront = shapePosition +
     new Vector3(1.0f, 1.0f, 0.0f) * shapeSize;
    Vector3 bottomRightFront = shapePosition +
     new Vector3(1.0f, 0.0f, 0.0f) * shapeSize;
    Vector3 topLeftBack = shapePosition +
     new Vector3(0.0f, 1.0f, 1.0f) * shapeSize;
    Vector3 topRightBack = shapePosition +
     new Vector3(1.0f, 1.0f, 1.0f) * shapeSize;
    Vector3 bottomLeftBack = shapePosition +
     new Vector3(0.0f, 0.0f, 1.0f) * shapeSize;
    Vector3 bottomRightBack = shapePosition +
     new Vector3(1.0f, 0.0f, 1.0f) * shapeSize;

    Vector3 topLeftFront2 = shapePosition +
     new Vector3(0.0f, 1.0f, 0.0f) * shapeSize;
    Vector3 bottomLeftFront2 = shapePosition +
     new Vector3(0.0f, 0.0f, 0.0f) * shapeSize;
    Vector3 topRightFront2 = shapePosition +
     new Vector3(1.0f, 1.0f, 0.0f) * shapeSize;
    Vector3 bottomRightFront2 = shapePosition +
     new Vector3(1.0f, 0.0f, 0.0f) * shapeSize;
    Vector3 topLeftBack2 = shapePosition +
     new Vector3(0.0f, 1.0f, 1.0f) * shapeSize;
    Vector3 topRightBack2 = shapePosition +
     new Vector3(1.0f, 1.0f, 1.0f) * shapeSize;
    Vector3 bottomLeftBack2 = shapePosition +
     new Vector3(0.0f, 0.0f, 1.0f) * shapeSize;
    Vector3 bottomRightBack2 = shapePosition +
     new Vector3(1.0f, 0.0f, 1.0f) * shapeSize;

    Vector3 topLeftFront3 = shapePosition +
     new Vector3(0.0f, 1.0f, 0.0f) * shapeSize;
    Vector3 bottomLeftFront3 = shapePosition +
     new Vector3(0.0f, 0.0f, 0.0f) * shapeSize;
    Vector3 topRightFront3 = shapePosition +
     new Vector3(1.0f, 1.0f, 0.0f) * shapeSize;
    Vector3 bottomRightFront3 = shapePosition +
     new Vector3(1.0f, 0.0f, 0.0f) * shapeSize;
    Vector3 topLeftBack3 = shapePosition +
     new Vector3(0.0f, 1.0f, 1.0f) * shapeSize;
    Vector3 topRightBack3 = shapePosition +
     new Vector3(1.0f, 1.0f, 1.0f) * shapeSize;
    Vector3 bottomLeftBack3 = shapePosition +
     new Vector3(0.0f, 0.0f, 1.0f) * shapeSize;
    Vector3 bottomRightBack3 = shapePosition +
     new Vector3(1.0f, 0.0f, 1.0f) * shapeSize;

    Vector3 frontNormal = new Vector3(0.0f, 0.0f, 1.0f) * shapeSize;
    Vector3 backNormal = new Vector3(0.0f, 0.0f, -1.0f) * shapeSize;
    Vector3 topNormal = new Vector3(0.0f, 1.0f, 0.0f) * shapeSize;
    Vector3 bottomNormal = new Vector3(0.0f, -1.0f, 0.0f) * shapeSize;
    Vector3 leftNormal = new Vector3(-1.0f, 0.0f, 0.0f) * shapeSize;
    Vector3 rightNormal = new Vector3(1.0f, 0.0f, 0.0f) * shapeSize;

    Vector2 textureTopLeft = new Vector2(1f * shapeSize.X, 0.0f * shapeSize.Y);
    Vector2 textureTopRight = new Vector2(0.0f * shapeSize.X, 0.0f * shapeSize.Y);
    Vector2 textureBottomLeft = new Vector2(1f * shapeSize.X, 1f * shapeSize.Y);
    Vector2 textureBottomRight = new Vector2(0.0f * shapeSize.X, 1f * shapeSize.Y);

    // Front face.
    shapeVertices[0][0] = new VertexPositionNormalTexture(
     topLeftFront, frontNormal, textureTopLeft);
    shapeVertices[0][1] = new VertexPositionNormalTexture(
     bottomLeftFront, frontNormal, textureBottomLeft);
    shapeVertices[0][2] = new VertexPositionNormalTexture(
     topRightFront, frontNormal, textureTopRight);
    shapeVertices[0][3] = new VertexPositionNormalTexture(
     bottomLeftFront, frontNormal, textureBottomLeft);
    shapeVertices[0][4] = new VertexPositionNormalTexture(
     bottomRightFront, frontNormal, textureBottomRight);
    shapeVertices[0][5] = new VertexPositionNormalTexture(
     topRightFront, frontNormal, textureTopRight);

    // Back face.
    shapeVertices[1][0] = new VertexPositionNormalTexture(
     topLeftBack, backNormal, textureTopRight);
    shapeVertices[1][1] = new VertexPositionNormalTexture(
     topRightBack, backNormal, textureTopLeft);
    shapeVertices[1][2] = new VertexPositionNormalTexture(
     bottomLeftBack, backNormal, textureBottomRight);
    shapeVertices[1][3] = new VertexPositionNormalTexture(
     bottomLeftBack, backNormal, textureBottomRight);
    shapeVertices[1][4] = new VertexPositionNormalTexture(
     topRightBack, backNormal, textureTopLeft);
    shapeVertices[1][5] = new VertexPositionNormalTexture(
     bottomRightBack, backNormal, textureBottomLeft);

    // Top face.
    shapeVertices[2][0] = new VertexPositionNormalTexture(
     topLeftFront2, topNormal, textureBottomLeft);
    shapeVertices[2][1] = new VertexPositionNormalTexture(
     topRightBack2, topNormal, textureTopRight);
    shapeVertices[2][2] = new VertexPositionNormalTexture(
     topLeftBack2, topNormal, textureTopLeft);
    shapeVertices[2][3] = new VertexPositionNormalTexture(
     topLeftFront2, topNormal, textureBottomLeft);
    shapeVertices[2][4] = new VertexPositionNormalTexture(
     topRightFront2, topNormal, textureBottomRight);
    shapeVertices[2][5] = new VertexPositionNormalTexture(
     topRightBack2, topNormal, textureTopRight);

    // Bottom face.
    shapeVertices[3][0] = new VertexPositionNormalTexture(
     bottomLeftFront2, bottomNormal, textureTopLeft);
    shapeVertices[3][1] = new VertexPositionNormalTexture(
     bottomLeftBack2, bottomNormal, textureBottomLeft);
    shapeVertices[3][2] = new VertexPositionNormalTexture(
     bottomRightBack2, bottomNormal, textureBottomRight);
    shapeVertices[3][3] = new VertexPositionNormalTexture(
     bottomLeftFront2, bottomNormal, textureTopLeft);
    shapeVertices[3][4] = new VertexPositionNormalTexture(
     bottomRightBack2, bottomNormal, textureBottomRight);
    shapeVertices[3][5] = new VertexPositionNormalTexture(
     bottomRightFront2, bottomNormal, textureTopRight);

    // Left face.
    shapeVertices[4][0] = new VertexPositionNormalTexture(
     topLeftFront3, leftNormal, textureTopRight);
    shapeVertices[4][1] = new VertexPositionNormalTexture(
     bottomLeftBack3, leftNormal, textureBottomLeft);
    shapeVertices[4][2] = new VertexPositionNormalTexture(
     bottomLeftFront3, leftNormal, textureBottomRight);
    shapeVertices[4][3] = new VertexPositionNormalTexture(
     topLeftBack3, leftNormal, textureTopLeft);
    shapeVertices[4][4] = new VertexPositionNormalTexture(
     bottomLeftBack3, leftNormal, textureBottomLeft);
    shapeVertices[4][5] = new VertexPositionNormalTexture(
     topLeftFront3, leftNormal, textureTopRight);

    // Right face.
    shapeVertices[5][0] = new VertexPositionNormalTexture(
     topRightFront3, rightNormal, textureTopLeft);
    shapeVertices[5][1] = new VertexPositionNormalTexture(
     bottomRightFront3, rightNormal, textureBottomLeft);
    shapeVertices[5][2] = new VertexPositionNormalTexture(
     bottomRightBack3, rightNormal, textureBottomRight);
    shapeVertices[5][3] = new VertexPositionNormalTexture(
     topRightBack3, rightNormal, textureTopRight);
    shapeVertices[5][4] = new VertexPositionNormalTexture(
     topRightFront3, rightNormal, textureTopLeft);
    shapeVertices[5][5] = new VertexPositionNormalTexture(
     bottomRightBack3, rightNormal, textureBottomRight);
 }

 public void SetTopTexture(Texture2D tex) {
    topTexture = tex;
 }
 public void SetSideTexture(Texture2D tex) {
    frontTexture = tex;
    backTexture = tex;
    leftTexture = tex;
    rightTexture = tex;
 }
 public void SetBottomTexture(Texture2D tex) {
    bottomTexture = tex;
 }

 public void RenderShape(GraphicsDevice device, Effect effect) {
    BuildShape();


    effect.Parameters["xTexture"].SetValue(topTexture);
    device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[2], 0, 2);
    effect.Parameters["xTexture"].SetValue(bottomTexture);
    device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[3], 0, 2);
    effect.Parameters["xTexture"].SetValue(frontTexture);
    device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[0], 0, 2);
    effect.Parameters["xTexture"].SetValue(backTexture);
    device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[1], 0, 2);
    effect.Parameters["xTexture"].SetValue(leftTexture);
    device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[4], 0, 2);
    effect.Parameters["xTexture"].SetValue(rightTexture);
    device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[5], 0, 2);

 }

在我的游戏中，Draw方法如下：

cubeEffect.CurrentTechnique = cubeEffect.Techniques["Textured"];
   foreach(EffectPass pass in cubeEffect.CurrentTechnique.Passes) {
      pass.Apply();
      BasicShape s = new BasicShape(new Vector3(1, 1, 1), new Vector3(0, 0, 3));
      s.SetTopTexture(TextureLoader.GetTexture(4));
      s.SetSideTexture(TextureLoader.GetTexture(35));
      s.SetBottomTexture(TextureLoader.GetTexture(4));
      s.RenderShape(GraphicsDevice, cubeEffect);   

  }

你可以看到，我正在加载不同的纹理，但结果是这样的：

我的立方体 http://www.tinyimg.org/images/769MinecraftClassic_2011_.bmp

我确定纹理是不同的，但是同一纹理被绘制在所有面上。我需要为每个面单独创建一个效果吗？那肯定会很麻烦。

你验证过 TextureLoader.GetTexture(35) 返回的值是否符合你的期望吗？ - ChrisF
@ChrisF - 嗯，纹理35是唯一显示的纹理，所以我认为它就是。而且，如果我将RenderShape中绘制代码的前两行放在最后，它会渲染纹理4。因此，它只渲染了最后应用的纹理。 - Bevin
那似乎是有用的信息，你应该在你的问题中包含它。不过我无法提供答案 - 我对XNA不是很熟悉。 - ChrisF
1个回答
6

在调用EffectPass.Apply()之前，设置在效果上的任何参数都不会生效。这是因为对效果进行更改是昂贵的，你可能想一次性执行多个更改。

您的RenderShape函数应该类似于：

public void RenderShape(GraphicsDevice device, Effect effect)
{
    BuildShape();

    foreach (EffectPass pass in effect.CurrentTechnique.Passes)
    {
        effect.Parameters["xTexture"].SetValue(topTexture);
        pass.Apply();
        device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[2], 0, 2);

        effect.Parameters["xTexture"].SetValue(bottomTexture);
        pass.Apply();
        device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[3], 0, 2);

        effect.Parameters["xTexture"].SetValue(frontTexture);
        pass.Apply();
        device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[0], 0, 2);

        effect.Parameters["xTexture"].SetValue(backTexture);
        pass.Apply();
        device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[1], 0, 2);

        effect.Parameters["xTexture"].SetValue(leftTexture);
        pass.Apply();
        device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[4], 0, 2);

        effect.Parameters["xTexture"].SetValue(rightTexture);
        pass.Apply();
        device.DrawUserPrimitives(PrimitiveType.TriangleList, shapeVertices[5], 0, 2);
    }
}
@Empyrean - 那么，您是说这不是推荐的方法吗？有什么更快的方法吗？我需要绘制很多这样的立方体，所以我需要尽可能地优化它。 - Bevin
通常情况下，您只能进行几百个状态更改（称为批处理）之后，就会遇到性能问题。在您的代码中，每个立方体的渲染由6个批次组成。这意味着在您的帧速率开始变得不可接受之前，您可能只能渲染少于100个立方体。您希望尽可能少地调用绘制，因此请在一个绘制调用中绘制所有立方体面，并使用相同的纹理。最好将六个纹理合并为单个纹理（纹理图集）。此外，在PC上，顶点缓冲比DrawUserPrimitive调用快得多。 - Empyrean
最快的方法是使用纹理合并，并在一个调用中渲染所有的立方体，根据立方体是否移动，可以使用静态或动态顶点缓冲区。如果其中一些立方体不移动，对于这些立方体使用静态顶点缓冲区，对于移动的立方体使用动态顶点缓冲区。此外，应该使用索引来避免重复使用顶点。重复使用的顶点需要进行变换，而且它们可能会以稍微不同的方式进行变换，从而在网格中产生接缝。 - Empyrean
@Empyrean - 我该如何处理图集呢？需要使用顶点的纹理坐标吗？那么我需要在一个大的纹理地图上找到每个纹理的坐标？ - Bevin
警告一下。材质图集和多级纹理映射不太兼容（参见http://blogs.msdn.com/b/shawnhar/archive/2009/10/22/texture-filtering-mipmapped-sprite-sheets.aspx）。我认为最好的选择是保持纹理分离，但使用单个纹理在一次渲染中呈现所有几何体。这应该可以使您的批次数量保持较小，除非在同一场景中包含大量独特的纹理。如果您正在执行此操作，可以通过修剪落在视锥之外的立方体来减少场景中每个唯一纹理的数量和批次。 - Empyrean
显示剩余3条评论
网页内容由stack overflow 提供, 点击上面的
可以查看英文原文，
原文链接