Terry Butler » DirectX 11

Ray Tracing #5

Terry — Sat, 12 Dec 2009 18:06:28 +0000

Things have been a little slow recently. I’ve been generally reading about other aspects of graphics programming as well as generally being busy and now I’ve come down with something. Blocked ear, runny nose, bad headaches, dizziness and more.

My best excuse for not getting as much programming done has to be that I’ve given coffee a bit of a hiatus for a while just to get some of the benefits of caffeine back. Good for the health though! …

I’ve still managed to get the majority of the ray tracer working in a DirectX 11 Compute Shader (working on DirectX 10 hardware using CS_4_0), although I have some small issues that I can’t track down before I can release a screenshot that looks identical to what I already have put up, albeit at 100 times better performance

Unfortunately there are no recursive functions allowed in the Compute Shaders, which means that I’m going to need to rethink stuff like the reflection traces and whatnot.

DirectX 11 (and DirectX in general) is still weird to work with, but slowly, things are coming together.

On a side note, I spent some of today looking at the Quake source and thinking about how cool a DirectX 11 port might be.

DirectX 11 Update – Driver Issues

Terry — Sat, 05 Dec 2009 11:45:44 +0000

I came across my first significant bug in the DirectX 11 Compute Shaders (Using CS_4_0 for compatibility with my DirectX 10 card) although it’s my fault for using old drivers

When filling my RWStructuredBuffer with something easy to debug such as:

float4(1.1, 2.2, 3.3, 4.4);

What actually occurred, when checking on both the CPU and GPU (via pixel shader), was the following:

float4(1.1, 1.1, 1.1, 1.1);

The X or R component is overwriting all of the other components (Y, Z, W aka G, B, A)

It required a simple driver update from the current Windows 7 “Windows Update” drivers of 191.xx to 195.62.

Problem fixed.

Impending DirectX 11 based fun

Terry — Thu, 03 Dec 2009 15:43:33 +0000

I’ve just started dabbling with DirectX 10 and learnt enough to convert the basic Microsoft triangle demo over to DirectX 11, which is my primary goal given the nifty compute shaders. It’s worth noting that it’s quite a savage humbling to be taken back to being capable of rendering just a single primitive to the screen, I can tell you that

I’ve decided to finally learn DirectX after all these years of using OpenGL and a portion of time spent using XNA, which has been a decent intermediary to give me a bit of background on Direct3D (Change from right-handed to left-handed matrix, changing to GLSL from to HLSL, etc) and my first DirectX 11 project will be biting off more than I can chew by using the compute shaders in DirectX 11 to accelerate ray tracing.

It’ll be refreshing to be working on something graphics programming related that is current and isn’t catching up on something that happened anywhere from 5 to 20 years ago, which has been the case right up until now. At least as far as DirectX 11 goes anyway.. Ray tracing on the other hand, is like a plethora of graphics programming techniques, in that the algorithms and/or concepts have been around for years, but only now are they becoming a possibility in real-time rendering.

As far as the compute shaders go, they are quite a different experience and will take some getting used to. I hope to post some progress over the next week or two.