[zj]

Hi, I test it on the teapot. It is rendered with different light angle and absorbing coefficient.
It must use multiple shadow maps for arbitrary geometry with a lot of overlapping parts. Ideally, you should use a semi-dome of light, but it is not practical.
I don't know how to use softshadow instead since we need to sample the shadow map for distance.
I want the shader to be easy to control and work at all view point. Not has dozens of parameters to tweak and only works as "back lighting".

[sabotage3d]

COol like the technic used in SHREK fast sss but It is interesting to test it in motion animation
to see the behaviour of the light when it will be ready

[sabotage3d]

and add some displacement or bump to see is it really a cool sss
cause in flat object is one and on a human face is other anyway keep going

[zj]

Texturing is added to the translucency shader. Here is some test with procedural and painted textures.



It is nearly ready and it is time to test on more complex models.

[fewo]

Hi all, and good job ZJ
about
CLOUD shading, do you try too use shadow map or deep shadow to replace ray-marching approch ?
and about
SSS shading can you put rendering time for each frame and is it more powerfull than you last SSS from your site ?

and AGAIN GOOD JOB

[zj]

Hi, this is a new test on more complex model. The subsurface illuminace will definitely blur textures and flat displacements. The coral test intergrate some cheap direct illuminance(diffuse and specular) to show the displacement.





About the render time, I have not kept an accurate record. To use this shader, you have to pre-render 7 shadow maps, if texturing is needed, you need 7 additional reference maps. All the maps are rendered in seconds and can be reused. The final render of the coral takes 4 to 5 minutes on my PIII 550 box. Direct illuminace pass rendered in no more than 30 seconds. Of cource, I take time to do color correcting in post. I think the speed is quite acceptable.

Now the shader is not ready, but you can get a test from this link:
http://zj.digitalrendering.com/source/translucency.slim

It provide a light shader and a color function. Tutorial will be posted when the shader gets ready.

About the cloud shader, I think I should abandom ray-march for speed issue. Maybe ray-trace is a faster solution. I will try it soon.

[Edited on 29/9/2003 by zj]

[sabotage3d]

I have tested it but I have problems with lights and accurate them corectly
the domelight is transSpot as the domelight a shadow gen
a constant shader with color translucency something is not right
this is only the trans pass right

[sabotage3d]

this is test with not accurated properly lights but it is working this is the most important
This is an abstract object with some errors on the buffer but is a preview after 2 hours I will post
a human face to see is there limitaion and animation but I don't have ftp space to upload it
anyway this is for now it is a little bit slow 12 minutes the trans pass so an animtion of 50 frames
5 hours hmm I haven't this time for rendering I have to sleep

[sabotage3d]

here's some I hadn't enough time to play a little bit more

[sabotage3d]

the other two passes

[zj]

I am testing an animation. It is a very close-up shot, and this frame is what I've got until now. It needs some better texturing and I need more sleep.

I rename the color function to "subsurf", and it is useful to control a Constant shader. You may remap it to get some coloration. Always render subsurface scattering and direct illuminance into different passes, and combine them in post to adjust a correct portion of them.

To get a correct light direction, create a mtorcoordsys and input [coordsys sysShapename] in the space field. {0,0,-1} will be the uniform L direction. I will add Cl and Kl control to the light shader.

Test animation, shaders and documents will be posted very soon.

[zj]

Thanks Wang Xin for preparing the color map of the subsuface media. It looks much better now. The map is used in ImageMap in the reference map generations. It is quite softened in the primary render.

Here is the test animation, it is subsurface illuminance only.
http://zj.digitalrendering.com/img/subsurf_avi_divx.rar

I will post a document about how to use the shader soon.

[Edited on 30/9/2003 by zj]

[Edited on 30/9/2003 by zj]

[zj]

My Win2k crashed due to some hardware problem. It needs sometime to re-establish the work station. Maybe I shall buy a new computer now.

Here is the doc about the shader.
http://zj.digitalrendering.com/subsurface.htm

[zj]

I start a new attempt to render dense clouds in RAT, using more feazible deep shadow approach this time. The image is a render of a number of Sprites with noise procedural under a deep shadowed light. The movie of Contact is a real inspiration.

More tests at different light conditions.

[Edited on 11/10/2003 by zj]

[zj]

Some latest update of the shader. The Sprites are lighted by the back light. Set light intensity larger than 1, giving a nice eadge-glow to the cloud. PRMan's deep shadow is a really amazing tool to detect volume density.

[Edited on 11/10/2003 by zj]

[zj]

Tests on more particles generated using the fillvolume script. Since the cloud is constantly colored, the render seems to be lacking of details. It is necessary to find a way to paint the surface color and Kd channel to get more artistic controls.

[KiserSoze]

Hey ZJ...


I use Air and MayaMan...

Is there any way that you can convert those .slims into a .sl file that can be compiled against Air??



I'd love to try out your translucency and cloud shaders...



thanks...


KiserSoze

[zj]

.slim is the template scripts for RAT's shader management. It is some kind of TCL script adding UI elements to RSL codes. You can adjust arguments of the shader quickly and see the result interactively. As my knowledge, these is no way to convert .slim to .sl automatically. But any RenderMan shader writer can look up into the code and write .sl from it. However, many .slim templates are RAT specificed and call the tools only available by PRMan.

[Edited on 17/10/2003 by zj]

[zj]

You can even fly through the deep shadow cloud.

[zj]

A high-rez test. More than 16,000 sprite-type particles are shaded. One 1024 deep shadow map is used. The black matte is left for the rocks in the cloud.



Here is the test animation of the final composition. Motion blur is added in post to enhance the sense of speed.

Get the divx avi file here:

http://zj.digitalrendering.com/testimg/thru_cloud.avi