A small test with photon map

[GoncaloP]

The image is darker because when you are using very high photons subdivisions you also are increasing its dinamic range, if you use low subdivisions the image will be brighter too, but with less quality of light.

You can see this if you try the scene with direct computation, with very low subdivisions, each time you increse the subdivisions for secondary bounces the image gets darker too

Gonçalo

[GoncaloP]

Anyway, you can allways increse he photon map multiplier, its global and you dont need t calclatet it again...

Gonçalo

[pengo]

a question to the teacher!!

a question to the teacher!!

GONCALO

I would like to know if I have 2 large vray lights do I need more photons or less photons for these ?

Because trying with 800 subdivisions in every lights I get with the global photon map in fierst diffuse and second (to see the photon solution) only some little white spot (cirlce distant from each other) model is in millimeters and search dist o 5 and max density to 1

trying with simple model I can get good result but with this scene I don't know what's happen

the vray lights is big to all height of room and large as the two sides of the room


please help me

excuse my bad english and my continuous questions

[GoncaloP]

If the model is in millimeters, increase your max density to 10 or 100 not sure, and search dist to 50 or 500.

Gonçalo

[pengo]

I again me

I again me

maybe you hate me now!!!



CAn u send some image to explain the difference between the retrace threshold 0 and 2 or higher?

And wich is the lowest number of photons for a vray light and for a direct for an interior room?

please I often use to much photons because the ram (512MB) is not enough and the hard disk burn!!!

bye thanks in advance and excuse for the continuous questions but I want to learn to have results like yours

[ezrhythm]

Nice, but too slow.

Nice, but too slow. DUAL XEON here.. took 9 minutes.

[dusan]

Goncalo, you should reall write an ultimate tutorial on how to use photons because you rule!!

[dusan]

Whats the difference between leaving max density at 0, and setting it to 1, i mean, how come the highest quality is at 1? And how does vray set search distance when it's on auto? I mean, should i use auto?
I used to play with max photons and leave these other two default but i would get some weird results, posted some in my thread "WIP: bedroom".

[pengo]

I hope that goncalo.....

I hope that goncalo doesn't abandon vray for Final Render or Mental Ray

He is less present in this forum than previous

I'm jocking

He sure has to much work to do now

Or maybe he is tryng Mental ray for max6

He loves vray and he never leave vray for another renderer (like SUURLAND did for FR to Vray but I understand him) and he will never leave us without suggests on vray technique

I hope it

Bye Gons
Great Gons

[Theobarbosa]

Hi,

Can u put the floor and the glass params?
Thanks

[gladiool]

I have been playing around with the photon mapping, trying to make it work for me. Right now i have made this scene for testing.

Could someone give me some more advice to clean it up, and maybe get render times down. Right now it's 25 minutes on a dual XP2400.
It still has some nasty artifacts like under the raised walkway, and "light
bleeding"

Direct sunlight has diffuse depth 6000, the 3 vray lights 2500. All at multiplier 1. The rest of the settings are in the screenshot:





nice thread btw.

[restoeboemi]

a little question, does photon depends on render size like irradiance map?
can we calculate photon at 320x240, and use it for 2000x1500?

[Josele]

I don`t think soo. gpmap technique is independent of image size. In GPmap you work in unit scale and number of photons.

Jose

[dusan]

They are totally independant.

[mohinder01]

Hi GoncaloP,

Do you mind sharing the specs. of your computer.? Specifically how much memory. When i try to render your test file, my machine pages like crazy..is 512meg not enough these days?