Hi,
This is my second test but now with PRTvolume on object.
image01
image02
shadow-vfx.com/rnd/ship_krakatoa2.jpg
I have few questions, you can see on sails diffrent rotation volume look totaly diffrent, do i need to change something or?
This is image of ship
PRTVolume voxel spacing on object maybe have bug, when i use 0.03 on this scene everything is ok, soon as i try 0.025 render is black. Then i try to find last working value and 0.028 was ok.
Thanks
Igor
My general advice would be to use a larger scale.
A rule of thumb is to never go into resolutions where the voxel spacing has to be below 1.0 (1 cm in Maya).
The PRT Volume converter is at its core a raytracer that turns a surface shell to a level set and then fills each voxel with one or more particles.
The smaller the values you are working with, the higher the potential for rounding errors.
So try making everything 100 times bigger and see if the results will be better…
Hi Bobo,
Thanks alot i was thinking same thing for scale because max is always bigger unit scale.
So i rescale 100X and this is resault
And also video HD1080 - 185frames
shadow-vfx.com/rnd/ship_PRtvolume_1080p.mov
Igor
This is quite impressive, especially the fine detail.
I would suggest increasing the particle count in the hull (looks a bit spongy), and decreasing the particle count in the sails (they look too solid, and high density generally makes the level-set-related stepping more visible).
It looks like the option to override the Density channel per object is not implemented yet.
We should add it first thing tomorrow so you can tweak the look of the individual objects without changing their particle count.
With the current build, I would suggest adding more particles to the hull and then reducing the Lighting Pass Density (if it was 5.0 Exponent -2, try 1.0/-2 or 5.0/-3) to see if you can smooth out the sails while keeping the rest solid.
Also, if you are using non-jittered particle distribution for the sails, try jittered and see if it smooths out the stepping.
Can you post some stats like how many particles you rendered per frame and what the rendering times were like?
Here is a quick test from Krakatoa MX 2 with a curved plane over a flat plane.
The curved plane’s PRT Volume uses non-jittered distribution (grid-like), the flat plane is set to Jittered.
The total number of particles is 6.8 million in all 4 images.
In the first image below, the Final Density is used for Lighting Pass Density and is 5.0/-1 (default, equivalent to 0.5).
You can see the moire patterns and stepping clearly. The density is too high and particles are self-shadowing too much:
In the second image, I enabled the Lighting Pass Density and set it to half the Final Pass Density (1.0/-1, equivalent to 0.1).
The stepping in the curved surface is still visible, but less pronounced.
In the third image, I disabled the Lighting Pass Density again, but switched the curved surface’s PRT Volume to Jittered / Well Distributed.
The result is dark shadows, but the stepping is gone:
In the last image, I reenabled the Lighting Pass Density to reduce the shadows intensity, while keeping the Jittered distribution:
Hi Bobo,
Yes very interesting i will test more this was just to see if everything is working.
render 1920*1080 - 2-3per frame - 84811214 particles
C:\2\ship\scenes\Maya2KSR\SCENE>C:\Python26\python.exe ship_Krakatoa_v03_0161.py
Section “Creating Particle Volume”:
Total 00h 00m 01.139s Called 1 times Avg 00h 00m 01.139s
Section “Creating Particle Volume”:
Total 00h 00m 10.062s Called 1 times Avg 00h 00m 10.062s
Section “Creating Particle Volume”:
Total 00h 00m 01.045s Called 1 times Avg 00h 00m 01.045s
Section “Creating Particle Volume”:
Total 00h 00m 01.139s Called 1 times Avg 00h 00m 01.139s
Section “Creating Particle Volume”:
Total 00h 00m 01.778s Called 1 times Avg 00h 00m 01.778s
Section “Creating Particle Volume”:
Total 00h 00m 00.749s Called 1 times Avg 00h 00m 00.749s
Section “Creating Particle Volume”:
Total 00h 00m 01.560s Called 1 times Avg 00h 00m 01.560s
Section “Creating Particle Volume”:
Total 00h 00m 01.139s Called 1 times Avg 00h 00m 01.139s
Section “Creating Particle Volume”:
Total 00h 00m 01.513s Called 1 times Avg 00h 00m 01.513s
Section “Creating Particle Volume”:
Total 00h 00m 01.638s Called 1 times Avg 00h 00m 01.638s
Section “Creating Particle Volume”:
Total 00h 00m 00.921s Called 1 times Avg 00h 00m 00.921s
Section “Creating Particle Volume”:
Total 00h 00m 00.670s Called 1 times Avg 00h 00m 00.670s
Section “Creating Particle Volume”:
Total 00h 00m 01.280s Called 1 times Avg 00h 00m 01.280s
Section “Creating Particle Volume”:
Total 00h 00m 00.218s Called 1 times Avg 00h 00m 00.218s
Section “Creating Particle Volume”:
Total 00h 00m 02.714s Called 1 times Avg 00h 00m 02.714s
Rendering frame 161
Using particle layout:
channel_map {
float32[3] Position;
float16[3] Color;
float16[3] Lighting;
float16 Density;
};
Section “Retrieving Particles”:
Total 00h 00m 22.261s Called 1 times Avg 00h 00m 22.261s
Total number of particles to be rendered: 84811214
splat_lighting_impl::compute_lighting()
light: light
resolution: (size2t 512, 512 )
filter: 1
Calculating Lighting: light - Progress: 0/0 (33.3333%) splat
_lighting_impl::compute_lighting()
light: light
resolution: (size2t 512, 512 )
filter: 1
Calculating Lighting: light - Progress: 0/0 (66.6667%) splat
_lighting_impl::compute_lighting()
light: light
resolution: (size2t 512, 512 )
filter: 1
Calculating Lighting: light - Progress: 0/0 (100%) Section "
Lighting:Updating Light":
Total 00h 00m 00.000s Called 3 times Avg 00h 00m 00.000s
Section “Lighting:Sorting Particles”:
Total 00h 00m 18.610s Called 3 times Avg 00h 00m 06.203s
Section “Lighting:Calculating”:
Total 00h 00m 58.423s Called 3 times Avg 00h 00m 19.474s
Rendering: Drawing 84811214 particles - Progress: 84811214/84811214 (75%)
Rendering: Drawing 84811214 particles - Progress: 84811214/84811214 (75%)
Rendering: Drawing 84811214 particles - Progress: 84811214/84811214 (75%)
Section “Rendering:Matte”:
Total 00h 00m 00.000s Called 0 times
Section “Rendering:Sorting”:
Total 00h 00m 06.286s Called 1 times Avg 00h 00m 06.286s
Section “Rendering:Drawing”:
Total 00h 00m 06.506s Called 1 times Avg 00h 00m 06.506s
0:01:53.770000
Press any key to continue . . .
This is better scene, with Bobo tip,
and also few more things 
shadow-vfx.com/rnd/ship_Krakatoa_v04.jpg
Thanks Bobo
Igor
thats funny!
cb
