Terrain rendering using DirectX

Graphics and GPU Programming Programming

Started by Bake September 27, 2011 02:29 PM

7 comments, last by Jason Z 12 years, 6 months ago

100

Author

September 27, 2011 02:29 PM

Hello!

I'm getting a stack overflow runtime error when my vertex/index buffers exceed a certain size. What I'm trying to do is to render a huge terrain generated using noise functions.

How can I avoid that problem? I'm using native C++ and DirectX 11.

Here's the render function:



void Render()

{

	float color[4] = {0.2f, 0.3f, 0.4f, 1.0f};

	g_pImmediateContext->ClearRenderTargetView(g_pRenderTargetView, color);



	ConstantBuffer cb;

	cb.mWorld = XMMatrixTranspose(g_World);

	cb.mView = XMMatrixTranspose(g_View);

	cb.mProjection = XMMatrixTranspose(g_Projection);

	g_pImmediateContext->UpdateSubresource(g_pConstantBuffer, 0, NULL, &cb, 0, 0);



	g_pImmediateContext->VSSetShader(g_pVertexShader, NULL, 0);

	g_pImmediateContext->VSSetConstantBuffers(0, 1, &g_pConstantBuffer);

	g_pImmediateContext->PSSetShader(g_pPixelShader, NULL, 0);

	g_pImmediateContext->DrawIndexed(WIDTH * HEIGHT * 6, 0, 0);



	g_pSwapChain->Present(0, 0);

}

A size of 128 * 128 (128 * 128 * 2 triangles) is working fine but 200 * 200 (and above of course) causes a stack overflow error.

Thanks in advance!

Jason Z

6,437

September 27, 2011 04:16 PM

How large is the vertex buffer you are using to do the drawing?

Jason Zink :: DirectX MVP

Direct3D 11 engine on CodePlex: Hieroglyph 3

Direct3D Books: Practical Rendering and Computation with Direct3D 11, Programming Vertex, Geometry, and Pixel Shaders
Articles: Dual-Paraboloid Mapping Article :: Parallax Occlusion Mapping Article (original):: Fast Silhouettes Article

Games: Lunar Rift

Bake

100

Author

September 27, 2011 04:54 PM

Vertex buffer:



SimpleVertex vertices[(WIDTH + 1) * (HEIGHT + 1)];

// Here all the vertices are added

D3D11_BUFFER_DESC bd;

ZeroMemory(&bd, sizeof(bd));

bd.Usage = D3D11_USAGE_DEFAULT;

bd.ByteWidth = sizeof(SimpleVertex) * (WIDTH + 1) * (HEIGHT + 1);

bd.BindFlags = D3D11_BIND_VERTEX_BUFFER;

bd.CPUAccessFlags = 0;

Index buffer:



WORD indices[WIDTH  * HEIGHT  * 6];

// ...

bd.Usage = D3D11_USAGE_DEFAULT;

bd.ByteWidth = sizeof(WORD) * WIDTH * HEIGHT * 6;

bd.BindFlags = D3D11_BIND_INDEX_BUFFER;

bd.CPUAccessFlags = 0;

After reading this thread I suspect that the index buffer is the problem because

the max. index with WORD indices is 65535[/quote].

ArthurD

100

September 27, 2011 07:20 PM

Exactly, you have pinned down the origin of your problem yourself, a WORD is a 16 bit integer, so your unsigned indice can't go over 65535.

If you use a DWORD instead (double word), you have up to 32 bits to store your indices.

unbird

8,359

September 27, 2011 07:54 PM

I doubt it. Even with the big grid he gets only 201*201 = 40401 vertices. Also, if that was really the matter, I rather expect a wrong rendering or a DX API call failure than a stack overflow.

I suspect the error coming from this



  SimpleVertex vertices[(WIDTH + 1) * (HEIGHT + 1)];

This big array will be created on the stack. Does it exceed your currently set stack size (or the default size which is I think 1 Mb ) ?
Rather create the temp array on the heap with new (don't forget to delete[] afterwards). Edit: Same applies to indices, of course.

It would help to know when the stack overflow is thrown.

Bake

100

Author

September 27, 2011 08:05 PM

You are right unbird. It's working now, thanks for your help!

I should probably learn some more C++ before messing around with DirectX.

Jason Z

6,437

September 28, 2011 05:23 AM

I doubt it. Even with the big grid he gets only 201*201 = 40401 vertices. Also, if that was really the matter, I rather expect a wrong rendering or a DX API call failure than a stack overflow.

I suspect the error coming from this

SimpleVertex vertices[(WIDTH + 1) * (HEIGHT + 1)];

This big array will be created on the stack. Does it exceed your currently set stack size (or the default size which is I think 1 Mb ) ?
Rather create the temp array on the heap with new (don't forget to delete[] afterwards). Edit: Same applies to indices, of course.

It would help to know when the stack overflow is thrown.

16 bit indices should also have been a problem - he is using 6 indices for each quad. This means that it would be 200*200*6 = 240,000. Although I am sure that the stack overflow is caused by the problem you described...

Jason Zink :: DirectX MVP

Direct3D 11 engine on CodePlex: Hieroglyph 3

Games: Lunar Rift

Tasche

222

September 28, 2011 06:09 AM

16 bit indices should also have been a problem - he is using 6 indices for each quad. This means that it would be 200*200*6 = 240,000. Although I am sure that the stack overflow is caused by the problem you described...[/quote]

but the maximum index value would still be 40k-something, since hes only got 40k vertices, and therefore fit into an unsigned short. if he wanted to use WORD for indexing into the index array he would have a problem, but that is only done by the GPU itself...
anyway, if your vertexarray has less than 2^16 entries (65k), WORD is a suitable index size, no matter how many indices are in the index buffer.
sorry for being a smartass

cheers,
tasche

Jason Z

6,437

September 28, 2011 08:35 AM

16 bit indices should also have been a problem - he is using 6 indices for each quad. This means that it would be 200*200*6 = 240,000. Although I am sure that the stack overflow is caused by the problem you described...

but the maximum index value would still be 40k-something, since hes only got 40k vertices, and therefore fit into an unsigned short. if he wanted to use WORD for indexing into the index array he would have a problem, but that is only done by the GPU itself...
anyway, if your vertexarray has less than 2^16 entries (65k), WORD is a suitable index size, no matter how many indices are in the index buffer.
sorry for being a smartass

cheers,
tasche
[/quote]That is right I missed the fine point there...

Jason Zink :: DirectX MVP

Direct3D 11 engine on CodePlex: Hieroglyph 3

Games: Lunar Rift

Terrain rendering using DirectX

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Terrain rendering using DirectX

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines