I created a mesh in blender which I am importing (by saving as a 3ds, 
then converting in poseray), to use as a "heightfield".  My plans are to 
use this in an animation, and I need this mesh at a pretty high level of 
detail as the scene is quite large and I'm doing I "fly-through" type 
animation.  I have 3 Q's about using this mesh.

1) In terms of rendering time, would it be quicker to use the mesh, or 
to convert the mesh into a 16-bit height_field, like what is done in the 
height_field tutorial of the documentation?

2) If rendering the mesh is faster, how do I determine the size of the 
mesh?  I know it's not coming in as a 1x1x1 sized object, like the 
height_field would be.  In my test run, centering required that I 
translate it by <0.05,0.1375,0.34>, and even that is my best guess.

3) According to the documentation, a Mesh2 object is better (and faster) 
for povray.  If their any convenient way to convert my mesh into a mesh2?

Thanx for your help

Bryan

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Bryan Heit <bjh### [at] nospamucalgaryca> wrote:
> 1) In terms of rendering time, would it be quicker to use the mesh, or 
> to convert the mesh into a 16-bit height_field, like what is done in the 
> height_field tutorial of the documentation?

  A height_field should render faster than a mesh, but take into account
that height_field uses a different normal smoothing algorithm than meshes,
so it may end up looking different at places.

  Try both to see what happens.

> 2) If rendering the mesh is faster, how do I determine the size of the 
> mesh?  I know it's not coming in as a 1x1x1 sized object, like the 
> height_field would be.  In my test run, centering required that I 
> translate it by <0.05,0.1375,0.34>, and even that is my best guess.

  You can use min_extent() and max_extent() to get the opposite corners
of the bounding box of the mesh (which povray calculates automatically).
AFAIK with a mesh the bounding box should be a perfect fit.

> 3) According to the documentation, a Mesh2 object is better (and faster) 
> for povray.  If their any convenient way to convert my mesh into a mesh2?

  A mesh2 is only faster to parse compared to mesh. Once parsed, there's
no difference.

  Are you sure poseray doesn't support saving as a mesh2? That would be
strange, given that it's a rather new program.
  If not, perhaps try to find another converter. Or as a last resort,
try this:

http://warp.povusers.org/WinMeshcomp30_beta3.zip

-- 
                                                          - Warp

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Bryan Heit wrote:
> I created a mesh in blender which I am importing (by saving as a 3ds, 
> then converting in poseray), to use as a "heightfield".  My plans are to 
> use this in an animation, and I need this mesh at a pretty high level of 
> detail as the scene is quite large and I'm doing I "fly-through" type 
> animation.  I have 3 Q's about using this mesh.
> 
> 1) In terms of rendering time, would it be quicker to use the mesh, or 
> to convert the mesh into a 16-bit height_field, like what is done in the 
> height_field tutorial of the documentation?
> 
> 2) If rendering the mesh is faster, how do I determine the size of the 
> mesh?  I know it's not coming in as a 1x1x1 sized object, like the 
> height_field would be.  In my test run, centering required that I 
> translate it by <0.05,0.1375,0.34>, and even that is my best guess.
> 
> 3) According to the documentation, a Mesh2 object is better (and faster) 
> for povray.  If their any convenient way to convert my mesh into a mesh2?
> 
> Thanx for your help
> 
> Bryan

Bryan,

PoseRay only exports Mesh2. So if you used PoseRay you already have the 
mesh in mesh2 format. Also in the exported files the comments at the top 
contain statistics about the geometry.

later,

FlyerX

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FlyerX wrote:
> Bryan,
> 
> PoseRay only exports Mesh2. So if you used PoseRay you already have the 
> mesh in mesh2 format. Also in the exported files the comments at the top 
> contain statistics about the geometry.
> 
> later,
> 
> FlyerX

You are correct - my bad.  Reading the geometry file I see you're the 
author of poseray.  Thanx for the great tool.

Bryan

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Warp wrote:
> Bryan Heit <bjh### [at] nospamucalgaryca> wrote:
>> 1) In terms of rendering time, would it be quicker to use the mesh, or 
>> to convert the mesh into a 16-bit height_field, like what is done in the 
>> height_field tutorial of the documentation?
> 
>   A height_field should render faster than a mesh, but take into account
> that height_field uses a different normal smoothing algorithm than meshes,
> so it may end up looking different at places.
> 
>   Try both to see what happens.


It looks like there is a break-even point.  If my height_field is over 
~1800x1800 in size it becomes marginally slower then the mesh (actually 
a mesh2, as FlyerX pointed out).  Even though I want a very large 
height_field (probably 2800x2800), I'm still going to use the 
height_field I can subdivide the height_field into separate files, and 
selectively include the appropriate files as they come into field within 
the animation.


Thanx for your help.

Bryan

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