Reflections with GI sec rays/sec GI light

[Michael B.]

Hello everybody,

I want to show you all some results from playing with a small project of Tomas Egger (Bug Tracker issue #9).

1. There are some strange reflections on the backside wall. I think they come from the photonmap of a radial light in GI sec mode.

2. Same scene rendered without photonmap (of rad GI sec light) is without this strange reflections.

3. Turning off this rad GI sec light and adding a new light (type camera) in sec GI mode produces other reflections in the sphere.

4. Using GI sec rays (20) instead of a light in GI sec mode produces other reflections again.

It seems that pic 4 shows the most realistic reflections.

This is done with EIAS 8, IntelMac 2,6, OSX 10.6.2

I also noticed the shadow of the sphere isn't as round as the sphere itself. But increasing the latitude/longitude settings from 18 to e.g. 36 makes the shadow nicely round.

I thought this could be useful for you.

Best

Michael

[Tomas Egger]

Ola Michael,

Really interesting test..

Thank you very much

Tom

[Igors]

Hello Michael

Please upload project

[Michael B.]

Hello Igors,

project is here: Files / FTPUpload / BUG Folder / Camera BUG Folder / Reflection.zip

It is the project of Tomas Egger (Bug Tracker issue #9)

Best

Michael

[Igors]

Hi All

1) About test project: if we consider 10 things together, so most probably no one problem will be found :rolleyes: Thus we've simplified prj, there are 2 lights: Light Object (white quad)) and RT light (no soft shadow, visible red spot in reflections). Both do emit photons

2) Quadratic dropoff should be set for lights with photon emission. Otherwise photon map can be far away of direct/GI illumination. Although Area Lights (and Light Objects) can be used without such dropoffs, it does not produce correct results and usable "as is"

3) Walls planes were made with "Cast Shadow" = off. Here it gives no speed advantages, but kills photons' bounces (if an object casts no shadow, so photons should pass thru as it's a fully clipped surface, isn't it?)

4) The attached image shows reflections calculated fast (just use photon maps) and fully (rays count = 50 for both: GI and Area Light). Sure that fast reflections are less accurate but they can be usable (especially for blurred ones)