• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
Migi0027

OpenGL
DX11 - Shaders - Writable Textures

25 posts in this topic

Hi guys, wink.png

 

I'm researching techniques for scene voxelization, and so far, only few papers has been found, but I found a great one! So now I'm in the process of creating the shader, but a problem stroke my mind, the paper is based on OpenGl (Theory is the same), and OpenGl has completely re-writable textures, in the shader, like so:

imageStore(voxelColor, voxelPos, outColor);

// voxelColor -> 3D Texture
// voxelPos   -> xyz Position of texture
// outColor, well, the data needed to be written

How can this be achieved with Directx 11 with HLSL? (Maybe I forgot something... Like usual tongue.png )

 

Thanks, as usual!

-MIGI0027

0

Share this post


Link to post
Share on other sites

Thanks for making me aware of that, but I thought that you could only output data from the computer shader, is it possible to write to it in the pixel shader?

0

Share this post


Link to post
Share on other sites
On D3D11/SM5 hardware yes; compute and pixel are the only stages which can write out.

D3D11.1 expands UAV support to all stages so you can write from basically anywhere.
1

Share this post


Link to post
Share on other sites

Sorry to annoy you further, but I have one last question regarding this topic.

 

Q: Do you send the 3D Texture (in this case), just like a read only shader resource [DeviceContext->XSSetShaderResources(....)], or do they require a different method?

 

-MIGI0027

0

Share this post


Link to post
Share on other sites

You don't use a shader resource view, you need to create an unordered access view (UAV) for the texture that you want to write to. To bind it to a compute shader you use CSSetUnorderedAccessViews, and to a pixel shader you use OMSetRenderTargetsAndUnorderedAccessViews.

2

Share this post


Link to post
Share on other sites

Hi again, thanks btw! happy.png

 

Another question...

 

How would one send such a resource to the GPU for reading to the PS, without setting any render targets. Here's my questions:

  • When calling OMSetRenderTargetsAndUnorderedAccessViews, if you set the backbuffer, numRTS, RTS to NULL, does it set the render targets to NULL, or does it skip the placement of the render targets.
  • Is there a way of treating the content of an UAV as a SRV?

Thanks

-MIGI0027

0

Share this post


Link to post
Share on other sites

When calling OMSetRenderTargetsAndUnorderedAccessViews, if you set the backbuffer, numRTS, RTS to NULL, does it set the render targets to NULL, or does it skip the placement of the render targets.

Not that I have tried (never used UAVs with pixel shaders), but docs are somewhat clear.

Specify NULL to set none.

If that doesn't work, use a array with explicit NULLs.
 

Is there a way of treating the content of an UAV as a SRV?


Nope, it's a different view, you have to create one. IIRC one can create an arbitrary amount of views for any resource. You only need to make sure that the corresponding bind flag was set when creating the resource and you don't have read/write hazards. So in this case don't bind both the UAV and SRV at once. You won't need to anyway, UAVs are read and write. Not saying that it is always a good idea to do, sometimes a ping-pong approach with two resources is better or even the only possibility.

By the way: You made me curious. You don't mind posting links to that papers, please ? Edited by unbird
0

Share this post


Link to post
Share on other sites

Btw. Why didn't they make another function of this, as they waste processing power by checking if the number of render targets is 0?

 

I know it's such a small operation, but everything counts. happy.png

 

Is there any specific reason for this?

 

-MIGI0027

0

Share this post


Link to post
Share on other sites
Ah yeah, Crassin et.al, thanks. You're in for some challenge then if you really wanna go octrees (I for one haven't done hierarchical structures on the GPU yet). Good luck.
 
I got you additional food for thought. The GPU Pro 4 books also has a chapter about voxelization. You can save you the money: The Ph.D. thesis from Mr. Gaitatzes about it is available on his site. Nice, since papers are usually a bit... brief.
0

Share this post


Link to post
Share on other sites

An error has come up, which I am for now unable to understand (I understand it, just don't know why tongue.png ).

 

Error:

maximum ps_5_0 UAV register index (8) exceeded - note that the minimum index is 5.

Relevant shader code: (Some resources are repeated or have some weird name, but that's because I'm moving stuff around)

RWTexture3D<float> t_gi0 : register(t0); // GD: These are all faces of a cube map
RWTexture3D<float> t_gi1 : register(t1); // Though i could construct them to one final cube map
RWTexture3D<float> t_gi2 : register(t2); // But I'm too lazy to do that now...
RWTexture3D<float> t_gi3 : register(t3); // After it works I might change it
RWTexture3D<float> t_gi4 : register(t4); // These are only for reading
RWTexture3D<float> t_gi5 : register(t5); // They have already been written to...

// pos and dir are in texture space
// dir is the direction from the center of the voxel outward
// dir should be normalized
float4 voxelFetch(float3 pos, float3 dir, float lod)
{
	float4 sampleX =
		dir.x < 0.0
		? t_gi0[pos]
		: t_gi1[pos];
	
	float4 sampleY =
		dir.y < 0.0
		? t_gi2[pos]
		: t_gi3[pos];
	
	float4 sampleZ =
		dir.z < 0.0
		? t_gi4[pos]
		: t_gi5[pos];
	
	float3 sampleWeights = abs(dir);
	float invSampleMag = 1.0 / (sampleWeights.x + sampleWeights.y + sampleWeights.z + .0001);
	sampleWeights *= invSampleMag;
	
	float4 filtered = 
		sampleX * sampleWeights.x
		+ sampleY * sampleWeights.y
		+ sampleZ * sampleWeights.z;
	
	return filtered;
}

// origin, dir, and maxDist are in texture space
// dir should be normalized
// coneRatio is the cone diameter to height ratio (2.0 for 90-degree cone)
float4 voxelTraceCone(float3 origin, float3 dir, float coneRatio, float maxDist)
{
	float3 samplePos = origin;
	float4 accum = float4(0, 0, 0, 0);

	// the starting sample diameter
	float minDiameter = minVoxelDiameter;

	// push out the starting point to avoid self-intersection
	float startDist = minDiameter;
	
	float dist = startDist;

	[loop]
    [allow_uav_condition]
	while (dist <= maxDist && accum.w < 1.0)
	{
		// ensure the sample diameter is no smaller than the min
		// desired diameter for this cone (ensuring we always
		// step at least minDiameter each iteration, even for tiny
		// cones - otherwise lots of overlapped samples)
		float sampleDiameter = max(minDiameter, coneRatio * dist);
		
		// convert diameter to LOD
		// for example:
		// log2(1/256 * 256) = 0
		// log2(1/128 * 256) = 1
		// log2(1/64 * 256) = 2
		float sampleLOD = log2(sampleDiameter * minVoxelDiameterInv);
		
		float3 samplePos = origin + dir * dist;
		
		float4 sampleValue = voxelFetch(samplePos, -dir, sampleLOD);
		
		float sampleWeight = (1.0 - accum.w);
		accum += sampleValue * sampleWeight;
		
		dist += sampleDiameter;
	}
	
	// decompress color range to decode limited HDR
	accum.xyz *= 2.0;
	
	return accum;
}

#endif

Texture2D t_alphamap : register(t0);
Texture2D t_dffalpha : register(t1);
Texture2D gBuffer_Shadows : register(t2);
Texture2D t_rFront : register(t3);
Texture2D t_rBack : register(t4);

#if COMPILENORMALMAP == 1
Texture2D t_norm : register(t5);
#endif
#if COMPILESPECULARMAP == 1
Texture2D t_spec : register(t6);
#endif
#if COMPILEMASKMAP == 1
Texture2D t_mask : register(t7);
#endif

SamplerState ss;

Now what on earth did I do wrong?

-MIGI0027

0

Share this post


Link to post
Share on other sites

You can't tell me it's impossible to send more than 6 UAVs, or maybe I'm setting it to the wrong slots, with the wrong range.

 

OpenGL GLSL for what I'm trying to achieve:

layout(binding = 3) uniform sampler3D voxelTex[6];

HLSL:

RWTexture3D<float> t_gi[6];

wacko.png

0

Share this post


Link to post
Share on other sites
Nope for SM5 it should be 8 UAVs. I checked with the compiler and the funny thing you are doing (at least two posts ago) is binding a read-write resource to a t# register, which would actually be a SRV. The compiler doesn't complain, it puts them into the UAV slots. Furthermore, a non RW resource goes into the SRV slots, even when marked with u# register. Again no compiler warning. It helps to look at the assembly. Example:

Buffer<float> In1 : register(u0);  // WRONG: It should be t#
RWBuffer<float> Out1: register(t0); // AGAIN WRONG: It should be u#
RWBuffer<float> Out2: register(t1);
RWBuffer<float> Out3: register(t2);
RWBuffer<float> Out4: register(t3);
RWBuffer<float> Out5: register(t4);
RWBuffer<float> Out6: register(t5);
RWBuffer<float> Out7: register(t6);
RWBuffer<float> Out8: register(t7);

[numthreads(4,4,4)]
void main(uint3 tid : SV_DispatchThreadID) 
{
    uint index = dot(tid, uint3(1, 8, 256)); // whatever
    Out1[index] = In1[index] + 
        Out2[index] +
        Out3[index] +
        Out4[index] +
        Out5[index] +
        Out6[index] +
        Out7[index] +
        Out8[index];        
}
 
This is where the slots end up:

// Generated by Microsoft (R) HLSL Shader Compiler 9.30.960.8229
//
//
//   fxc /Zi /T cs_5_0 /Fo stub.fxo /Fx stub.asm stub.fx
//
//
// Resource Bindings:
//
// Name                                 Type  Format         Dim Slot Elements
// ------------------------------ ---------- ------- ----------- ---- --------
// In1                               texture   float         buf    0        1
// Out1                                  UAV   float         buf    0        1
// Out2                                  UAV   float         buf    1        1
// Out3                                  UAV   float         buf    2        1
// Out4                                  UAV   float         buf    3        1
// Out5                                  UAV   float         buf    4        1
// Out6                                  UAV   float         buf    5        1
// Out7                                  UAV   float         buf    6        1
// Out8                                  UAV   float         buf    7        1
(Resource type [tt]texture[/tt] means t# register, hence the t).
Same happens if one doesn't use the register keyword at all.

So I expect other RW-resources on your side - where you probably only read from. If so, don't use RW.
0

Share this post


Link to post
Share on other sites

Thanks, first time using UAVs wacko.png .

 

Though I have a problem, the u's seemed to solve some problems, the pixel shader outputs to 5 different render targets (Can be boiled down to 3-4). So then the UAVs expect to start at an index of at least u5, but the max UAV register index is 8, and I need six slots, but this doesn't obey the laws.
 

UAV registers live in the same name space as outputs, so they must be bound to at least u5, manual bind to slot u0 failed

What would be your suggestion?

Edited by Migi0027
0

Share this post


Link to post
Share on other sites

Ah-ha, there's the culprit. Learned something new then - haven't used UAVs in pixel shaders so far.

 

Seems you have to tailor your setup accordingly. Multiple passes ? Combine two or more resources into one (say, use a bigger texture and "atlas"/split manually) ? How's it done in OpenGL ? Is there no such limit ?

 

For multiple passes look into both stream out (geometry shader) and append/consume buffers (special UAVs, hopefully they work in pixel shaders) maybe they can help you split the problem.

 

Admittedly, these are hints from a bird's eye view. This really sounds like a challenging problem. Look into alternatives: If something gets too cumbersome another approach is likely better than "shoehorning" it into a unsuitable API. That thesis I linked looks feasable with D3D11 (first variant using geometry shaders and three passes).

0

Share this post


Link to post
Share on other sites

Actually I might just be able to boil the number of render targets to 3, but that's the minimum, the thing is that I'm using the approach of deferred rendering, which consumes some render targets.

 

Btw. How on earth do you combine 6 3d cube map faces into one whole 3d cube map, never heard of this being done with 3d textures, maybe it's not possible yet...

0

Share this post


Link to post
Share on other sites

Well, this is what I do:

 

...

Do the Voxelisation (done, kinda)

...

Render the scene with Vox Data, output to different RTS (Deferred Rendering).

 

So I'm not actually writing to the UAV's anymore, that has already been done, can I send the UAVs without being in this writing stage?

0

Share this post


Link to post
Share on other sites

I guess I could have a separate pass, where only one color is being set in the pixel shader, the GI only color, then sample it on top to the scene.

0

Share this post


Link to post
Share on other sites

You can make a shader resource view for your UAV buffer and use that in the shader stage as a texture input (Texture3D, etc). There's no need to use the UAVs at this point anymore. :)

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Similar Content

    • By Toastmastern
      So it's been a while since I took a break from my whole creating a planet in DX11. Last time around I got stuck on fixing a nice LOD.
      A week back or so I got help to find this:
      https://github.com/sp4cerat/Planet-LOD
      In general this is what I'm trying to recreate in DX11, he that made that planet LOD uses OpenGL but that is a minor issue and something I can solve. But I have a question regarding the code
      He gets the position using this row
      vec4d pos = b.var.vec4d["position"]; Which is then used further down when he sends the variable "center" into the drawing function:
      if (pos.len() < 1) pos.norm(); world::draw(vec3d(pos.x, pos.y, pos.z));  
      Inside the draw function this happens:
      draw_recursive(p3[0], p3[1], p3[2], center); Basically the 3 vertices of the triangle and the center of details that he sent as a parameter earlier: vec3d(pos.x, pos.y, pos.z)
      Now onto my real question, he does vec3d edge_center[3] = { (p1 + p2) / 2, (p2 + p3) / 2, (p3 + p1) / 2 }; to get the edge center of each edge, nothing weird there.
      But this is used later on with:
      vec3d d = center + edge_center[i]; edge_test[i] = d.len() > ratio_size; edge_test is then used to evaluate if there should be a triangle drawn or if it should be split up into 3 new triangles instead. Why is it working for him? shouldn't it be like center - edge_center or something like that? Why adding them togheter? I asume here that the center is the center of details for the LOD. the position of the camera if stood on the ground of the planet and not up int he air like it is now.

      Full code can be seen here:
      https://github.com/sp4cerat/Planet-LOD/blob/master/src.simple/Main.cpp
      If anyone would like to take a look and try to help me understand this code I would love this person. I'm running out of ideas on how to solve this in my own head, most likely twisted it one time to many up in my head
      Thanks in advance
      Toastmastern
       
       
    • By fllwr0491
      I googled around but are unable to find source code or details of implementation.
      What keywords should I search for this topic?
      Things I would like to know:
      A. How to ensure that partially covered pixels are rasterized?
         Apparently by expanding each triangle by 1 pixel or so, rasterization problem is almost solved.
         But it will result in an unindexable triangle list without tons of overlaps. Will it incur a large performance penalty?
      B. A-buffer like bitmask needs a read-modiry-write operation.
         How to ensure proper synchronizations in GLSL?
         GLSL seems to only allow int32 atomics on image.
      C. Is there some simple ways to estimate coverage on-the-fly?
         In case I am to draw 2D shapes onto an exisitng target:
         1. A multi-pass whatever-buffer seems overkill.
         2. Multisampling could cost a lot memory though all I need is better coverage.
            Besides, I have to blit twice, if draw target is not multisampled.
       
    • By mapra99
      Hello

      I am working on a recent project and I have been learning how to code in C# using OpenGL libraries for some graphics. I have achieved some quite interesting things using TAO Framework writing in Console Applications, creating a GLUT Window. But my problem now is that I need to incorporate the Graphics in a Windows Form so I can relate the objects that I render with some .NET Controls.

      To deal with this problem, I have seen in some forums that it's better to use OpenTK instead of TAO Framework, so I can use the glControl that OpenTK libraries offer. However, I haven't found complete articles, tutorials or source codes that help using the glControl or that may insert me into de OpenTK functions. Would somebody please share in this forum some links or files where I can find good documentation about this topic? Or may I use another library different of OpenTK?

      Thanks!
    • By Solid_Spy
      Hello, I have been working on SH Irradiance map rendering, and I have been using a GLSL pixel shader to render SH irradiance to 2D irradiance maps for my static objects. I already have it working with 9 3D textures so far for the first 9 SH functions.
      In my GLSL shader, I have to send in 9 SH Coefficient 3D Texures that use RGBA8 as a pixel format. RGB being used for the coefficients for red, green, and blue, and the A for checking if the voxel is in use (for the 3D texture solidification shader to prevent bleeding).
      My problem is, I want to knock this number of textures down to something like 4 or 5. Getting even lower would be a godsend. This is because I eventually plan on adding more SH Coefficient 3D Textures for other parts of the game map (such as inside rooms, as opposed to the outside), to circumvent irradiance probe bleeding between rooms separated by walls. I don't want to reach the 32 texture limit too soon. Also, I figure that it would be a LOT faster.
      Is there a way I could, say, store 2 sets of SH Coefficients for 2 SH functions inside a texture with RGBA16 pixels? If so, how would I extract them from inside GLSL? Let me know if you have any suggestions ^^.
    • By KarimIO
      EDIT: I thought this was restricted to Attribute-Created GL contexts, but it isn't, so I rewrote the post.
      Hey guys, whenever I call SwapBuffers(hDC), I get a crash, and I get a "Too many posts were made to a semaphore." from Windows as I call SwapBuffers. What could be the cause of this?
      Update: No crash occurs if I don't draw, just clear and swap.
      static PIXELFORMATDESCRIPTOR pfd = // pfd Tells Windows How We Want Things To Be { sizeof(PIXELFORMATDESCRIPTOR), // Size Of This Pixel Format Descriptor 1, // Version Number PFD_DRAW_TO_WINDOW | // Format Must Support Window PFD_SUPPORT_OPENGL | // Format Must Support OpenGL PFD_DOUBLEBUFFER, // Must Support Double Buffering PFD_TYPE_RGBA, // Request An RGBA Format 32, // Select Our Color Depth 0, 0, 0, 0, 0, 0, // Color Bits Ignored 0, // No Alpha Buffer 0, // Shift Bit Ignored 0, // No Accumulation Buffer 0, 0, 0, 0, // Accumulation Bits Ignored 24, // 24Bit Z-Buffer (Depth Buffer) 0, // No Stencil Buffer 0, // No Auxiliary Buffer PFD_MAIN_PLANE, // Main Drawing Layer 0, // Reserved 0, 0, 0 // Layer Masks Ignored }; if (!(hDC = GetDC(windowHandle))) return false; unsigned int PixelFormat; if (!(PixelFormat = ChoosePixelFormat(hDC, &pfd))) return false; if (!SetPixelFormat(hDC, PixelFormat, &pfd)) return false; hRC = wglCreateContext(hDC); if (!hRC) { std::cout << "wglCreateContext Failed!\n"; return false; } if (wglMakeCurrent(hDC, hRC) == NULL) { std::cout << "Make Context Current Second Failed!\n"; return false; } ... // OGL Buffer Initialization glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT); glBindVertexArray(vao); glUseProgram(myprogram); glDrawElements(GL_TRIANGLES, indexCount, GL_UNSIGNED_SHORT, (void *)indexStart); SwapBuffers(GetDC(window_handle));  
  • Popular Now