Questions tagged [directx]
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33
questions
13
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2
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Derivative maps vs. Tangent Space Normal maps
I discovered that some engines use derivative maps instead of tangent space normal maps.
After some reading, it seems to be a really awesome way to replace tangent space normals but are there some ...
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8
votes
2
answers
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Help me grasp Anisotropic Filtering (AF)
Lately I've been reading about texture filtering, namely Nearest-neighbor filtering, Bilinear filtering, Trilinear filtering, Anisotropic filtering, MIP maps, RIP Maps and so on.
From a high-level ...
4
votes
1
answer
834
views
Clipping for perspective projection
In the following two graphs,
the red lines are borders of the perspective-projection frustum,
the blue lines are to be rasterized,
the green lines are perspective-projection lines, which are wrong.
...
- 591
4
votes
0
answers
80
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Drawing "after" Present to achieve better performance
I had an application that was originally single threaded and worked as follows:
gather the items to be drawn (occlusion / frustrum culling / sorting into batches)
draw items using an immediate ...
- 323
2
votes
1
answer
213
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Is it possible to make a projection matrix to not project in the center?
I have the following projection matrix:
and I need to make a hole in the center of my matrix, something like that: (I don't want to project a custom W and H)
Is that possible ? Thanks.
- 23
2
votes
1
answer
268
views
Why does DirectX use COM pointers and interfaces?
I have a rudimentary understanding of COM and I know that its main purpose is to enable interoperability between programs written in different languages. However I dont understand why that is useful ...
- 291
2
votes
1
answer
333
views
Image saved as DDS with 16f format in photoshop has strange FOURCC text
I am analyzing the hex code for DDS files which are compressed via Nvidia's dds plugin in photoshop.
I noticed something strange when having a 16 bit float file. This is the dialog:
When I look at ...
- 123
2
votes
1
answer
364
views
Rendering equation for spherical lights
I am currently implementing spherical lights in my DirectX game engine. I decided to build the shading formula from the classical rendering equation. Here is what I get:
The simplifications show that ...
- 23
2
votes
1
answer
301
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DX9 Shadow map PCF issue
I am trying to do simple PCF with Unity but I am facing some issues and I don't know where they come from. If anybody has an idea...
Here are two examples
...
- 1,219
2
votes
0
answers
153
views
If statements in shaders - implications and consequences [duplicate]
I've heard a lot that in shader development, you absolutely need to avoid branching and so if statements.
But why? Does this have a real impact on performances on old and modern hardware or is it ...
- 1,219
1
vote
0
answers
181
views
DDS BC7 Thumbnails on Windows 10
Is it possible to enable accurate thumbnail previews for DDS files that use the newer DX10 headers (DirectX 10 headers)? It seems there is very limited information about this.
I did find a couple ...
- 111
1
vote
0
answers
321
views
Compute shader in DirextX: difference between four kinds of memory barriers
There are four kinds of memory barriers in DirectX. Their names and definitions are:
DeviceMemoryBarrier: Blocks execution of all threads in a group until all ...
- 11
1
vote
0
answers
105
views
Conditionals and branching in shaders
This is a quite wide subject which implies a lot of topics such as the platform or the compiler, but I think that it could be useful for everyone to know more about this.
A common mistake is to think ...
- 1,219
1
vote
0
answers
233
views
OpenGL/D3D11 offscreen render multiple buffering
Recently I've been looking at Vulkan, and one thing that I noticed is that the application is responsible for choosing which buffer to render to in the case of multiple buffering.
This got me thinking:...
- 11
1
vote
0
answers
40
views
Optimizing texture fetches with higher mip levels
Let's say I have some shader program in DirectX or OpenGL rendering a full screen quad. And in a pixel/fragment shader I sample some huge textures at random texture coordinates. That is one same ...
- 193
1
vote
0
answers
151
views
D3D12EnableExperimentalFeatures causes D3D12CreateDevice to fail
I am following Nvidia's DXR tutorial: D3D12HelloTriangle. I call below code before creating device and it returns true
...
- 730
1
vote
0
answers
134
views
Rounding rules for mip level with point sampling
In shaders, when using SampleLevel intrinsic, if we pass 0.5 in the mip level parameter, and the sampler is a ...
- 623
0
votes
2
answers
212
views
Why do Nvidia and AMD have to update their drivers for game releases?
I like to know the technical aspects of it. Game developers use APIs like OpenGL or DirectX. The functions provided by these APIs, I would assume, work flawlessly with all graphic cards because they ...
0
votes
1
answer
189
views
Converting Vertex and Index buffers to a File Format
I have many sets of vertex and index buffers that I’d like to render on to the screen. Ideally each model in different locations with-in world space. I’m actually doing a statistical study on spatial ...
- 113
0
votes
1
answer
112
views
CPU load in games - what is the GPU/DirectX doing to make CPU load higher?
More of a question about what's possible in DX.
Some people have reported that when running games on higher settings they get less CPU load but when dropping the settings the CPU load increases.
...
- 101
0
votes
1
answer
84
views
DirectX FVF(Flexible Vertex Format ) equivalent in OpenGL/Vulkan?
Is there any directX FVF(Flexible Vertex Format ) equivalent in OpenGL/Vulkan.
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0
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1
answer
693
views
Billboarding in Vertex Shader
I'm trying to create a vertex shader that billboards a quad. Most resources online show the code to be some variation of the following
...
- 115
0
votes
1
answer
1k
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Calculating UV coordinates for sampling texture atlas
I have an 8192x8192 texture atlas that contains 1024x1024 shadow maps aligned side by side. I'm trying to calculate the uv coordinates so that I can sample each shadow map appropriately based on the '...
- 115
0
votes
1
answer
1k
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Sphere Texture Mapping Algorithm
I am trying to generate UV coordinates automatically to map a texture on a sphere.
The problem is with seams when going from 0.8 to 0.2 there is a discontinuity and interpolation in fragment shader ...
0
votes
1
answer
290
views
Weirdly looking diffuse irradiance map
I have problem with creating diffuse irradiance map. As reference I am using https://learnopengl.com/PBR/IBL/Diffuse-irradiance and https://github.com/TheEvilBanana/PhysicallyBasedRendering/blob/...
0
votes
0
answers
21
views
How to use unbound descriptor range properly in descriptor tables
I am trying to use 2 "D3D12_DESCRIPTOR_RANGE" in a root descriptor table,defined as follows:
...
- 119
0
votes
2
answers
120
views
Storing array of floats within shader
I am about to implement a framerate histogramm chart for a DirectX Renderer.
Ideally I would do this in pure shader code, but for a a histogramm I need to store the timestamps of the last ...
0
votes
0
answers
71
views
16 bit SNORM format not correctly storing Z component?
I generate a normal GBuffer in my engine, and I store it using a R16G16B16A16_SNORM format like this:
...
- 115
0
votes
1
answer
460
views
SSAO - artifacts appearing
I am trying to implement SSAO using DirectX11 but instead I got white screen with few black dots on model. My suspect is that kernel generation or usage might be wrong. I've tried changing order of ...
0
votes
1
answer
364
views
Skybox is rendered on the model instead of surroundings
I'm trying to implement Skybox in DirectX 11 (DirectXTK) but when I'm rendering skybox, then texture is rendered to my sphere model instead of showing skybox outside.
Rendering code:
...
0
votes
0
answers
168
views
Invoking shader in DX
So I am new to the DX12 world. I am currently trying to tweek the nbody_gravity DX12 sample, but appending or calling another Compute Shader which is to add 2 buffers to produce an output in a ...
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0
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0
answers
51
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DX12- hlsl code invoking [duplicate]
I am pretty new to graphics programming using DX12. I was testing out my skills by building a shader to add 2 buffers and put the result in an output buffer. I have written this code in "ComputeShader....
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1
answer
148
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When do people need to work directly with a graphical API (eg: Direct3D) instead of using already made software?
I had this doubt in my head for several months and have been unable to find an answer anywhere on internet.
I know what OpenGL, DirectX, Vulkan, Metal, etc... are, I already know what they are used ...
- 101