Messages

1

[Max] Resolved Feature Requests / Ior texture: remap values in [0, 1] range

« on: 2015-08-01, 12:51:40 »

Hi,

For the moment we can use a texture in the IOR channel, but the values have to be > 1 to be taken into account. So an intermediate process has to be applied to get hdr values from a 8bit texture.

Vray does a smart thing: the values < 1 correspond to 1/IOR. So a IOR of 1.5 is equal to a IOR of 0.666. It's a lot easier to use a texture for ior this way :)

What do you think ?
Nicolas

2

[Max] Resolved Bugs / Re: Corona 1.2 - Crash when bitmap is updated

« on: 2015-07-31, 23:40:50 »

My bad, thanks for the quick reply !

3

[Max] Resolved Bugs / Corona 1.2 - Crash when bitmap is updated

« on: 2015-07-31, 19:17:31 »

Hi,

While working on my PBR texture (Substance Designer to Corona) converter I found Corona made 3ds max crash as soon as a bitmap used by a material gets updated while the Interactive Render was running.
It crashes with both .png and .bmp (haven't tried other formats).

Tested on max 2015.

Nicolas

4

[Max] General Discussion / Re: GGX / maximum roughness compared to vray ?

« on: 2015-07-28, 19:40:33 »

I think in practice you can need it and it'd be a lot easier if everyone out there use the same convention.
Also it means that you can't convert Vray 3.2 materials that have specific glossiness values (and use GGX).

So, yeah, I think getting rid of this curve would be a good idea :)
Until then, if you can give me information on the curve, it can help me making the correct conversion in my filter, thanks!

5

[Max] General Discussion / GGX / maximum roughness compared to vray ?

« on: 2015-07-25, 23:03:39 »

Hi,

I'm working on various converters for Substance Designer/Painter, we'd like to provide users the ability to export maps for various renderers.
I made a first one for vray, it works very well and I now want to adapt it to corona.

I first had a problem with the ior texture: in vray the [1, 100] is remapped in the [0, 1] by simply doing 1/ior. It's really convenient as it allows the usage of a texture quite easily. In corona, even if a texture input is supplied for the ior, it seems it's stuck at 1. So I found a work around: I put a "CoronaMix" and made 1 Divided by my "1/ior" texture, to get the ior value back. it works! but it'd just be more convenient if you did the same trick as vray ;)

Another problem: the glossiness. Eventhough you say you have GGX implemented, it looks like you have applied a curve on the glossiness.. It can't produce as rough surfaces as it should when glossiness = 0.

In Substance Designer/Painter, we have implemented GGX without any changes from the paper, Chaos probably did the same because their glossiness really matches ours. But Corona seems very different..

This is the same setup, the material is
- diffuse black
- reflection white
- ior 100
- glossiness 0
- (ggx in vray)

Corona:


Vray: