OTOY Forums

Hey,

Very nice, but, if you have the time, can you try some stuff:

* use less polygons for the emitters. maybe place some quads in aluminium rectangles mounted into the ceiling ? (with normals pointing down)
this will impact the speed very much.

* the image is very uniformly lit. try localizing light, eg only have a few lightsources in corners of the room instead of one big chandelier, it will show a much better result of emitters,
and, play with the blackbody power. I'd make the ceiling quad (eg 2 triangles) lights halogen, (about 7000 degrees), and use one incandescent lightbulb at 2800 degrees), and try to keep the polycount on the lightbulb lower than 200.

If this all works fine, we're sure we've got a winner
Especially when you see the new suprise features (all brand new, much requested, render engine material and texture features) coming in the last non 'MLT equivalent' release, eg 2.3 v5 coming next week.

Radiance

The number of triangles for the bulbs is unacceptable for me.... You would have the same result with 1 trangle... There are many detailed light fixtures from evermotion or other companies but these must be used with renderers like mental ray and vray.. not with Octane... 1 triangle would give the same result... I know that you have to show a nice looking bulb but you could use 1/100 of the triangles and still look great...

Definitely, Reduce mesh faces (as much as you or the image quality can tolerate) on all rounded objects - Especially Emitters!

Use your host model application to reduce mesh on bulbs and if you need to, amp up the illumination power so the light bleed could mask the facets.
Also (it's up to you) but you may wish to increase the exposure or ISO values to increase the Ambient Illumination to your scene.
Unless you want it to look 'romantic'

I have installed my two brand new GTX 480 in my Cubix Box, and they have been close to burn ! As they are very close to each other in the Cubix, one is more cooled than the other, and in AUTO mode for the air fans, one of the card reached 101 degrees a short time. I have set the air fan speed to 100%, and now I get 73°C and 83°C for the two cards and a strong airplane noise !

Well, I have done some test and found a method that can be usefull to many people, to avoid a high amount of faces on the emitters.

In the image below, the two lanterns contain only 46 emitting faces, and the bulbs themselves are not emitting light.

The trick is simple : The bulbs can be low poly or high poly with subsurf. This has no importance !

Currently, for what i have seen and if I am not wrong, light can't pass through glass materials, but I have noticed a very useful thing : Diffuse materials with opacity set to zero still emit light ! This allows to get transparent and even totally unvisible objects to emit light !

In the example below, there are two kinds of emitters : inside each bulbs there is a small cube with diffuse emitting material. This light doesn't propagate beyond the bulb enveloppe, but the bulb itself is luminous.

- The bulbs are made of a specular material with high IOR.
- The external glass of the lanterns is made of diffuse emitting material with an opacity of 0.005. I kept a low value of opacity but without setting it to zero, in order to make the glass surface slightly visible. The power emitting value of the glass is 5 in the image below.

The interesting side of this method is that the scene uses only 46 emitting faces !

I hope that this method will help you !

Best regards,

Philippe.

ROUBAL wrote:OK, but why so many polygons for so simple shapes ? Would it be really noticeable with less ?

I have tried to model a flame bulb like yours, and I got 72 quad faces (144 triangles for one lamp with enough detail). From distance with smooth applied, you will not notice that it is not subsurfaced.

I applied a subsurf level of one and got 272 quad faces, so 544 triangles. For 5 lamps , you get 2720 triangles... still far under your 15000 triangles, and my original lamp extruded from a circle of 8 vertices was more detailed than necessary !

I set this model up in earlier release of octane and the model of the bulb had a very high poly count, since I modelled to much detail, I opened the OCS file and used the bulbs for emitting lights, not realising fully that there can be much improvement using a lower count.

Try to use unvisible emitting meshes and an emitting cube inside your lamps. Is requires very few GPU ressources !

No chandelier switched on this render.

Gee! Your modeling skills kick ass. I mean... how long did it took you to model all these? Did you use "ready" model that come from the net?
And last but not least how many triangle is the entire scene composed of?

The scene took over a week to make in 3dsMax. It has total of 715,000 triangles although could be different number since I still have a lot of modifiers still attached to objects. I probably build upon it as well, and add a lot more objects on top of the fireplace.

can you zip up and dropbox and email me this scene ?
( I won't share it, but will make a tutorial on interior lighting for realistic results and fast rendertimes )

?

Radiance