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# Naruto-kun

Member Since 15 Oct 2012
Offline Last Active Oct 17 2016 12:34 PM

### In Topic: Direction to point for lighting purposes

26 September 2016 - 11:48 PM

Perfect. Thanks a bunch.

### In Topic: Converting world rotation to body rotation

30 August 2016 - 01:17 PM

Thanks a bunch. Apologies for the misunderstanding.

### In Topic: Converting world rotation to body rotation

30 August 2016 - 12:34 AM

I need the camera rotation for custom 3D sound engine purposes. Since I didn't create the camera (it is created internally by the simulator and I have to use a bit of reverse engineering to get hold of it) I need to be able to transform it so that I know where it is looking relative to the nose of the aircraft.

### In Topic: Distance to a pixel

28 August 2016 - 01:07 PM

Looking over the output results, it appears that the x and y values of the vector after being multiplied by the inverse projection matrix are the angles to the pixel in radians (x converted to degrees is roughly -60 which fits with my horizontal FOV of 120 deg, and y is roughly 3.75 deg which fits my vertical FOV of 7.5 deg). I'm guessing the key is in what relationship the z and w values have with my far and near clip planes?

### In Topic: Distance to a pixel

28 August 2016 - 11:13 AM

Here is the geometry shader I am working with. The basic idea, is that the X axis of the texture (depth buffer) I am sampling from will correlate with the X axis of the final image, and the distance to the pixel calculated using the depth buffer will correspond to the Y axis of the final image (in otherwords, a modified B-scope radar display where the horizontal corresponds to the azimuth of the return and the vertical corrosponds to the slant range).

```[maxvertexcount(80)]
void GS( point GS_INPUT sprite[1], inout TriangleStream<PS_INPUT> triStream )
{
PS_INPUT v;

uint ux = sprite[0].id % 256;
uint uy = sprite[0].id / 256;
float x = float(ux) / 256.0f;
float y = float(uy) / 75.0f;
float x1 = x + (1.0f / 256.0f);
float y1 = y + (1.0f / 75.0f);

float4 fdepth = float4(
depth.SampleLevel(SampleType, float2(x, y1), 0),
depth.SampleLevel(SampleType, float2(x, y), 0),
depth.SampleLevel(SampleType, float2(x1, y1), 0),
depth.SampleLevel(SampleType, float2(x1, y), 0)
);
float4 v1 = float4((2.0f*x) - 1.0f, 1.0f - (2.0f*y1), fdepth.x, 1.0f);
float4 v2 = float4((2.0f*x) - 1.0f, 1.0f - (2.0f*y), fdepth.y, 1.0f);
float4 v3 = float4((2.0f*x1) - 1.0f, 1.0f - (2.0f*y1), fdepth.z, 1.0f);
float4 v4 = float4((2.0f*x1) - 1.0f, 1.0f - (2.0f*y), fdepth.w, 1.0f);

float4 m1 = mul(v1, inprj);
float4 m2 = mul(v2, inprj);
float4 m3 = mul(v3, inprj);
float4 m4 = mul(v4, inprj);

float l1 = length(m1.xyz / m1.w);
float l2 = length(m2.xyz / m2.w);
float l3 = length(m3.xyz / m3.w);
float l4 = length(m4.xyz / m4.w);

v.m = 0;
v.p.x = v1.x;
v.p.y = l1 - 1.0f;
v.p.zw = float2(0, 1.0f);
v.t = float2(x, y1);
triStream.Append(v);

v.p.x = v2.x;
v.p.y = l2 - 1.0f;
v.p.zw = float2(0, 1.0f);
v.t = float2(x, y);
triStream.Append(v);

v.p.x = v3.x;
v.p.y = l3 - 1.0f;
v.p.zw = float2(0, 1.0f);
v.t = float2(x1, y1);
triStream.Append(v);

v.p.x = v4.x;
v.p.y = l4 - 1.0f;
v.p.zw = float2(0, 1.0f);
v.t = float2(x1, y);
triStream.Append(v);
triStream.RestartStrip();
}
```
Here is the first sample, using the top left corner of the texture source image (dimensions are 256x75). The screenshot below gives you an idea of where the camera is looking. The actual texture source image would only contain a thin strip from the center of the screenshot.

```ux	0	uint
uy	0	uint
x	0.000000000	float
y	0.000000000	float
x1	0.003900000	float
y1	0.013300000	float
fdepth	x = 0.968700000, y = 0.964700000, z = 0.968600000, w = 0.964700000	float4
m1	x = -1.048700000, y = 0.063800000, z = -0.099900000, w = 1.068700000	float4
m2	x = -1.048700000, y = 0.065500000, z = -0.099900000, w = 1.064700000	float4
m3	x = -1.040500000, y = 0.063800000, z = -0.099900000, w = 1.068600000	float4
m4	x = -1.040500000, y = 0.065500000, z = -0.099900000, w = 1.064700000	float4
l1	0.987600000	float
l2	0.991300000	float
l3	0.980000000	float
l4	0.983700000	float
//Inverse projection matrix
inprj[0]	x = 1.048700000, y = 0.000000000, z = 0.000000000, w = 0.000000000	float4
inprj[1]	x = 0.000000000, y = 0.065500000, z = 0.000000000, w = 0.000000000	float4
inprj[2]	x = 0.000000000, y = 0.000000000, z = 0.000000000, w = 1.000000000	float4
inprj[3]	x = 0.000000000, y = 0.000000000, z = -0.099900000, w = 0.100000000	float4
```
Here is what the final output looks like. A bit confusing to say the least.

Here I have the camera even further from the target.

```ux	0	uint
uy	0	uint
x	0.000000000	float
y	0.000000000	float
x1	0.003900000	float
y1	0.013300000	float
fdepth	x = 0.999300000, y = 0.999200000, z = 0.999300000, w = 0.999200000	float4
m1	x = -1.048700000, y = 0.063800000, z = -0.099900000, w = 1.099300000	float4
m2	x = -1.048700000, y = 0.065500000, z = -0.099900000, w = 1.099200000	float4
m3	x = -1.040500000, y = 0.063800000, z = -0.099900000, w = 1.099300000	float4
m4	x = -1.040500000, y = 0.065500000, z = -0.099900000, w = 1.099200000	float4
l1	0.960000000	float
l2	0.960300000	float
l3	0.952600000	float
l4	0.952900000	float
//Inverse projection matrix
inprj[0]	x = 1.048700000, y = 0.000000000, z = 0.000000000, w = 0.000000000	float4
inprj[1]	x = 0.000000000, y = 0.065500000, z = 0.000000000, w = 0.000000000	float4
inprj[2]	x = 0.000000000, y = 0.000000000, z = 0.000000000, w = 1.000000000	float4
inprj[3]	x = 0.000000000, y = 0.000000000, z = -0.099900000, w = 0.100000000	float4
```
I hope this helps to give a better idea of what I'm trying to do.

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