Examples of the use of a bicubic patch as a camera

Might have the object camera patch done by the end of next week - no
promises though
The scene is just modified from the WinPOV insert menu
The bicubic patch is as follows but the type, etc don't matter, just the
control points
 bicubic_patch {
  type 1 flatness .001 u_steps 3 v_steps 3
      <-2.514948, 2.387680, -0.686198>, <-2.503437, 0.932466, 0.365123>,

      <-2.467564, -0.731072, 0.428970>, <-2.577552, -2.430063,
-0.645947>,
      <-0.777964, 2.655374, 1.447072>, <-0.747272, 1.034141, 2.959753>,
      <-0.711400, -0.629398, 3.023599>, <-0.670717, -2.332220,
1.742100>,
      <0.987450, 2.681504, 1.454497>, <1.018142, 1.060270, 2.967178>,
      <1.054015, -0.603269, 3.031025>, <1.094697, -2.306091, 1.749526>,
      <2.611443, 2.635919, -0.918698>, <2.792806, 1.010854, 0.387400>,
      <2.828679, -0.652684, 0.451247>, <0.765400, -0.313458, -0.708595>
}

--
Bye
Pabs

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Attachments:
Download 'biccam.png' (29 KB) Download 'normcam.png' (19 KB) Download 'envmap.png' (39 KB) Download 'reflect.png' (39 KB)

Preview of image 'biccam.png'

Preview of image 'normcam.png'

Preview of image 'envmap.png'

Preview of image 'reflect.png'

BTW They are

1. Bicubic_patch camera
2. Regular perspective camera
3. The image from 1 uv_mapping onto the bicubic_patch
4. The bicubic patch with finish {reflection 1}
--
Bye
Pabs

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Interesting. What uses do you see for it?

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"Tony[B]" wrote:

> Interesting. What uses do you see for it?

Mainly env mapping like the 3rd image

But you never know what the artists in
the POV community will come up with (Gilles)

--
Bye
Pabs

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What would be really neat is to have a bicubic patch as an area light since
it's got u and v built in and you could make all kind of shapes with it (like
a hemisphere).

-Mike

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MikeH wrote:

> What would be really neat is to have a bicubic patch as an area light

Yeah - U would have to sample many points on the patch to determine the amount of
light hitting the surface - bit like focal blur or use point lights distributed
all over the patch.

> since it's got u and v built in

What does that have to do with it - unless using point lights all over an object
- nothing much

> and you could make all kind of shapes with it (like a hemisphere).

Yep

--
Bye
Pabs

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> > What would be really neat is to have a bicubic patch as an area light
>
> Yeah - U would have to sample many points on the patch to determine the amount of
> light hitting the surface - bit like focal blur or use point lights distributed
> all over the patch.

You can kind of already do this with radiosity, but it takes too long to get a good
enough distribution of samples to make clear shadows visible.  What I'm talking about
is an area light just like the rectangular implimentation except with shadow ray
tested for a patch instead of a planar rectangle.

> > since it's got u and v built in
>
> What does that have to do with it - unless using point lights all over an object
> - nothing much

In block_area_light, replace the uv of the standard area light with the uv of a
bicubic patch.  You need the parameters of the shape to do more than 4 samples.

Anyway, just an idea but I think it would be neat.

-Mike

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