AJLynn

I'm a complete n00b at Brazil, never touched it before yesterday, but my firm owns it (there was a 3D guy here who bought it 4.5 ago and left 2 ago) and I'd like to see if I can figure it out before I go and buy Vray. I've been working with a model of my current architecture project that was done by a consultant. Are there still any Brazil people here who I can bug with questions?

I've got the latest 1.2 release on Max8, my model is one big editable poly, my materials are standard except some windows that are off-the-shelf Brazil glass. I've used a Brazil direct light with a giant radius for the sun and given it a smaller photon focus to hit the building and immediate surroundings. I'm using Mitch-Net at -1/3, global photon with 300000 photons from the sun and the rest of those settings at default, QMC at -3/0, sky light in direct and indirect with a slight blue.

First problem (there will be more): in the attached renders, I've got concrete block and brick materials that use the Tile map. The brick has color and bump maps, the block is gray with a bump map. In the parts that receive direct light, the bump works fine, but where it's in shadow it's relying on QMC to do the bump map and it gets these artifacts (I did some diagnostic renders showing GI samples and the artifacts happen where the samples aren't). I can kill the artifacts by bringing min rate up to 0 but that kills the render time. Is there a better way?

Attached Images

	problem1.jpg (65.0 KB, 76 views)
	problem2.jpg (53.9 KB, 66 views)

moshenko

Can you post your Luma Server settings for me? I used Brazil for a long time (although not recently) and I may be able to assist. Did you try posting on the Brazil forum?

Edit: Actually, you could probably try increasing your View Rate from the default (15) to something like 25 and see if that makes a difference (I think it should). If that doesn't help, post the settings and I would be happy to take a closer look.

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Nicholas Moshenko
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AJLynn

The View Rate seems to be working, thank you.

Next question

According to the entry on Regathering in the Brazil customers tutorial area, you get regather by turning on global photon and setting the Luma Server's bounces to 2. (The only place with Bounces control is the Sampling Control.) When I do this it just seems to darken the scene. Is there another step?

First image has Bounces=1, second has Bounces=2

Attached Images

	bounces-1.jpg (19.5 KB, 57 views)
	bounces-2.jpg (17.3 KB, 38 views)

moshenko

You are correct about regathering; there are no more steps needed. I suspect what's happening is this: your global photon solution is causing unusually bright areas on the inside of your building. If the sun is coming from above and behind the building as in your images, one wouldn't necessarily expect the interior to be as bright. This is probably the result of a very "general" photon solution, combined with the default estimate and radius values that produce overly bright illumination. When you enable regathering, you are seeing a "truer" lighting solution than you were with just photons. I'm pretty rusty in my photon theory and lingo, but I think that's what's going on in your case.

When I was using Brazil regularly I rarely used photons for exterior scenes for these same reasons. I found that they lead to more errors than just a plain QMC scene and that I spent much of my time trouble-shooting the photon settings. Straight QMC in Brazil can be pretty quick for exteriors so you may want to experiment with that. For an interior scene, regathered photons are the way to go, IMO.

Hope this helps -

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Nicholas Moshenko
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AJLynn

You're right, I should have caught that - mental ray would have given me the same problem, and I'd solve it with multi-bounce Final Gather instead of photons. Here, the photons must be bouncing into space, doing almost nothing productive but messing me up with sampling radius.

Justin Hunt

I'd second the non use of Photons for exteriors.

These are some general settings that I use for exteriors :

JHV

If you turn on Indirect Illumination, then be sure not to have the sky light do secondary bounces, only point, omni and area.

An other trick with skylight without indirect is to turn shadow casting Off for your ground. Its not physically correct but does allow for more light onto the sofits and deep recesses.

Attached Images

Brazil Ext Setings.jpg (101.3 KB, 29 views)

AJLynn

Thanks.

I think I'm starting to get the hang of this. First time I opened it and saw it had almost as many controls as mental ray has shaders, that was pretty alarming

Justin Hunt

They may seem like alot of controls, but in reality Brazil is very easy. I find that Brazil has one of the best image sampling quality.

Have fun

JHV

kippu

sorry mr justin... my bad

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Justin Hunt

what is it about Vray users, There is a world out there that isn't VRAY. They are almost as bad a Maxwell Flamers

This is clearly a thread for Brazil. If you dont have anything to contribute that is Brazil related please keep your thoughts and comments to yourself.

By the way I am a Vray user as well.

JHV