Mitsuba Exporter

[TwinSnakes007]

Had some requests to see screenshots of the features that are in progress..so here goes.

ICE Segment (Mitsuba Hair Shape)



Polygon Mesh (Mitsuba Serialized Shape)



ICE Point Cloud (Mitsuba Intersection Primitives)



ICE Point Cloud Instances [Mesh & Model] (Mitsuba ShapeGroup & Instance Shape)

[Tekano]

oh! very good. is it possible to export volumes from Softimage for Rendering with this yet?

[TwinSnakes007]

oh! very good. is it possible to export volumes from Softimage for Rendering with this yet?

Volumes will require a bit more effort and are low on the TODO list right now.

[Tekano]

ah thats a shame, was the only reason this renderer looking interesting to me. Is it possible to define geometry as a mitsuba 'shape' then export this ? perhaps I could then hand crank an xml file to render with these shapes as boundaries for the participating media shaders. some really interesting light and scattering phase functions are included with this renderer http://www.cs.cornell.edu/projects/stitchmeshes/

cheers!

**edit - oh I see your second example picture this is what you are doing! nice one, so I gather this functionality is not available yet **

[TwinSnakes007]

Is it possible to define geometry as a mitsuba 'shape' then export this ?

Defining 3D Volume data sets is an advanced feature. I need to add support for defining and exporting Shaders, Lights, Cameras, and Integrators first.

You can do the basic 'fog' type stuff by hand using the Homogeneous medium. Just define the medium and put stuff inside it by referencing the medium in all the scene objects.

Code: Select all

<medium type="homogeneous" id="fog">
..some settings...
</medium

<sensor>
...some settings...

 <!-- Put camera inside of fog -->
 <ref id="fog" />
</sensor

<emitter>
..some settings...

 <!-- Put light inside of fog -->
 <ref id="fog" />
</emitter>

.etc, .etc.

[Tekano]

yup thats what I was going to try first, thanks for reminding me about this great renderer and also for attempting to do the XSI exporter, am very grateful. will post pics if I get any success.

[TwinSnakes007]

ICE Particle Instancing

Got simple instancing working where the particle shape reference is a polygon mesh. Tomorrow I'll work on hierarchical instancing, where the particle shape reference points to a model that has (n) number of polygon mesh children underneath it.

EDIT:
Made some progress last night on supporting model instancing. Should be able to commit something tonight and show some screenshots.

EDIT (10/25/2012)
Since SI doesnt keep a list of referenced objects and after talking with Wenzel J. (creator of Mitsuba), I'm going to have to restructure the export once again to be able to handle Instancing.

[TwinSnakes007]

Finally got instancing working (with help from Wenzel Jacobs [Mitsuba creator]). The exporter now supports Model instancing as well.

Next up is fleshing out the recent Shaders that where added, and then Shader export.

-TS-

EDIT (10/27/2012)
After some testing, I'm really not happy with the increased export time. Gonna have to rework somethings to get the timings more acceptable.

[TwinSnakes007]

oh! very good. is it possible to export volumes from Softimage for Rendering with this yet?

Welp, here ya go. It only took me a couple hours....and this is just a proof of adherence to the file format....Mitsuba 3D Volume Grid Shape.




I generated the point data using a simple procedural formula. But it all works, and lends itself to being "ICE Data" friendly.

[TwinSnakes007]

Mitsuba Shader Support

[TwinSnakes007]

No pictures this time, but added support for:

Homogeneous and Heterogeneous Volumes
Cameras and Camera Shaders
Lights and Light Shaders

[forton]

Need a beta tester?

[TwinSnakes007]

Sure do. Waiting for Bug repository to be setup and then we'll put this puppy thru the paces.

-TS-

P.S. - Working on GridVolume at the moment. This will allow you to define Volume shapes using SI PointClouds & ICE.

GridVolume is how this was done:

[rimg=800]http://www.mitsuba-renderer.org/images/gallery/scarf-flakes.png[/rimg]

[TwinSnakes007]

Adding PointCloud generation of GridVolumes has been tough. The difficult part about adding this feature was not breaking the existing support for ConstVolume as well.

I had to rework the Heterogeneous shader definition to support both ways, and I think I'm good to go now. I thought this would take a day to do, its been like over a week.

I hope to post a video tonight of setup and result.

[Tekano]

sounds awesome, and incredibly complicated! looking forward to seeing your video.

how are gridvolumes being supported via Softimage? what format are they in to start with?

[TwinSnakes007]

how are gridvolumes being supported via Softimage? what format are they in to start with?

A GridVolume is a Volume composed of "cells" along each axis x,y,z. Each cell can have 3 properties: Density, Color, Orientation. So this data can easily be defined via PointClouds in Softimage. The hard part was coming up with a way to do that, so that its reasonably intuitive to an SI user.

So, after several different approaches, the cleanest way I could come up with is a combination of:

* Use the particle "color" attribute to set the cell Color property, the particle "mass" attribute to set the cell Density property, and the particle "force" attribute to set the cell Orientation property.

* Require a "Generate 3D Point Grid" node to be present on a ICE Tree. I read the values of this compound to set the x,y,z resolution of the GridVolume and to error check against the NbPoints attribute.

So, with that setup, you can do anything you want to the PointCloud, except one thing - Delete a point. The number of particles described by the ""Generate 3D Point Grid" node must equal the number of points in the PointCloud. Other than that limitation, you can set the values of those 3 properties by any means available to you in SI.