I'd just, for the first time, started playing with some polygonal models 
available on the internet, and I saw a great rendering on the Sunflow 
gallery page of a 3D scanned stone bust: 
http://sunflow.sourceforge.net/gallery/v0072/statue_ajax-jpeg.jpg
(from the gallery http://sunflow.sourceforge.net/index.php?pg=gall on 
Sunflows sourceforge page)

The model itself has about 540,000 polygons, and is available via 
http://forum.jotero.com/viewtopic.php?t=3&sid=b917ccdcb01d6651ec313e5192f9faf2

Since I'd not used high poly count models, or focal blur much, I though 
I'd just try to re-render the Sunflow picture using POVRay.

The test renders took about an hour or so, but for the final render I 
pumped up the settings and went to bed - I probably set them too high, 
as the render time was 10 hours 57 minutes in the end.

The focal blur was set to 100 samples, radiosity to 5 bounces, 
error_bound to 0.5, and the count to 900.

I converted the model using using Cross Roads 3D - which gave me a 142M 
POV source file. Are there any other utilities that can convert other 3D 
formats to POVRay? Something that supported mesh2 might be nice for example.

The model is lit from a single point light source, but the radiosity 
does a great job of making that look pretty realistic. The original 
Sunflow picture's author did a great job of posing and lighting the bust 
  - there's some real flair in that.

It's interesting to see the differences between the POVRay and Sunfow 
renders - I suspect that the Sunflow render was using less bounces.

I converted the HDR output to JPG in Photoshop, and adjusted the 
contrast and saturation to make it a closer match to the Sunflow one so 
I could compare them side to side.

Cheers,
Edouard.

Post a reply to this message

Attachments:
Download '540k-ajax.jpg' (125 KB)

Preview of image '540k-ajax.jpg'

Wasn't it Edouard Poor who wrote:
>I converted the model using using Cross Roads 3D - which gave me a 142M
>POV source file. Are there any other utilities that can convert other
>3D formats to POVRay? Something that supported mesh2 might be nice for
>example.

PoseRay will convert the OBJ file to a POV mesh2 object. The result is
54Mb of POV mesh2 data that renders in less than a minute (with just the
single light source that I believe PoseRay pulls from the obj file).

The only awkward thing is that the bust faces away from the camera, and
the camera, light and model are located in illogical places. So I had to
do this to rotate the model and put it back into view.

#declare C =  (min_extent(Poseray_scene_object) +
               max_extent(Poseray_scene_object))/2;

object{
      Poseray_scene_object
         translate -C
         rotate y*150
         translate C
      }


-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message

Here's what you get straight out of the box with PoseRay.
The only thing I've changed is that I rotated the model, as mention edin thge
previous post.

Post a reply to this message

Attachments:
Download 'ajax_jotero_com.jpg' (60 KB)

Preview of image 'ajax_jotero_com.jpg'

Mike Williams wrote:
> Wasn't it Edouard Poor who wrote:
>> I converted the model using using Cross Roads 3D - which gave me a 142M
>> POV source file. Are there any other utilities that can convert other
>> 3D formats to POVRay? Something that supported mesh2 might be nice for
>> example.
> 
> PoseRay will convert the OBJ file to a POV mesh2 object. The result is
> 54Mb of POV mesh2 data that renders in less than a minute (with just the
> single light source that I believe PoseRay pulls from the obj file).
> 
> The only awkward thing is that the bust faces away from the camera, and
> the camera, light and model are located in illogical places. So I had to
> do this to rotate the model and put it back into view.
> 
> #declare C =  (min_extent(Poseray_scene_object) +
>                max_extent(Poseray_scene_object))/2;
> 
> object{
>       Poseray_scene_object
>          translate -C
>          rotate y*150
>          translate C
>       }
> 
> 

Ahhh, great - I'll try with PoseRay in the future. I'd read that mesh2 
objects both parse faster, and take less space, both of which are good! 
I think the raw render speed was about the same - a minute or so with a 
single light source, and no radiosity or focal blur.

Thanks for the info!

Cheers,
Edouard.

Post a reply to this message

Mike Williams wrote:
> Here's what you get straight out of the box with PoseRay.
> The only thing I've changed is that I rotated the model, as mention edin thge
> previous post.

It's slightly hard to tell, but it looks like PoseRay also gets the 
proper smoothing of the polygons right as well - Cross Roads 3D seemed 
to leave me with a lot of planar polygons from it's cpomversion, even 
after I chose the "smooth triangles" option.

Thanks again for the pointer!

Cheers,
Edouard.

Post a reply to this message

Edouard Poor nous illumina en ce 2008-08-31 19:11 -->
> I'd just, for the first time, started playing with some polygonal models 
> available on the internet, and I saw a great rendering on the Sunflow 
> gallery page of a 3D scanned stone bust: 
> http://sunflow.sourceforge.net/gallery/v0072/statue_ajax-jpeg.jpg
> (from the gallery http://sunflow.sourceforge.net/index.php?pg=gall on 
> Sunflows sourceforge page)
> 
> The model itself has about 540,000 polygons, and is available via 
> http://forum.jotero.com/viewtopic.php?t=3&sid=b917ccdcb01d6651ec313e5192f9faf2 
> 
> 
> Since I'd not used high poly count models, or focal blur much, I though 
> I'd just try to re-render the Sunflow picture using POVRay.
> 
> The test renders took about an hour or so, but for the final render I 
> pumped up the settings and went to bed - I probably set them too high, 
> as the render time was 10 hours 57 minutes in the end.
> 
> The focal blur was set to 100 samples, radiosity to 5 bounces, 
> error_bound to 0.5, and the count to 900.
> 
> Cheers,
> Edouard.
> 
> ------------------------------------------------------------------------
> 
Radiosity with 5 bounces. Very slight time effect here. In that scene, most 
radiosity ray hit the backgrouns after the first bounce. Whenever you reach the 
background, you stop. You may also reach the adc_bailout well before you've done 
all the bounces. You should see little to no difference between 3 and 5 bounces 
in both time and quality.


-- 
Alain
-------------------------------------------------
You know you've been raytracing too long when you wonder if ground fog or 
athmosphere will look better for your company's market share pie chart.
Christoph Rieder

Post a reply to this message

I think you succeeded superbly in your lighting. Even with such a
simple trivial texture it looks very good.

Post a reply to this message

Warp <war### [at] tagpovrayorg> wrote:
> I think you succeeded superbly in your lighting. Even with such a
> simple trivial texture it looks very good.

I can't take any credit for the lighting and positioning of the statue - all I
did was copy the rendering on the Sunflow site as closely as I could - the
credit belongs to whoever did that original rendering ("Tartiflette" is all the
Sunflow page says).

There is no texturing either - just a slightly off-white pigment. It was the
inter-reflective lighting, simulated through radiosity in POVRay, that I found
fascinating.

Cheers,
Edouard.

Post a reply to this message

Superb image.

"Edouard Poor" <pov### [at] edouardinfo> wrote:

> It was the inter-reflective lighting, simulated through radiosity in POVRay, > that
I found fascinating.
>
> Cheers,
> Edouard.

you can give an example?

Post a reply to this message