Why are the vray demo files using VRayHDRI instead of regular bitmaps?

[evanmichalski]

I've yet to get a response from Chaosgroup so thought I'd ask you fellas, I've noticed a trend lately, specifically with Max 2017 and Vray 3.4 and up where their demo files have instead of just regular diffuse bitmaps, they're instead substituting VRayHDRI for the diffuse slot. Case in point:

(you can download the file in the description btw) when looking at some of the shaders, most if not all of them are VRayHDRI materials in the diffuse, reflect, and gloss slots. Is there any particular reason why they're choosing to go this route?

[Nicolai Bongard]

From a quick google search:

 

RyderSK

Re: Vray optimiation

It's bullshit advice, apart from UDK which has it from past almost no engine require such rule to optimise space required to minimize memory footage. It's ridicolous to do it in Vray to every single bitmap used. It saves zero space and zero time in 2012. Btw, I would never...never, listen to anything he has to say... for your own sake.

 

But there is available optimization when it comes to bitmaps in Vray 2.3. You can now load all types of bitmaps as VrayHDRi instead of regular Bitmap loader, and these should speed up especially render start up times. Other optimizations more for scene sake is to use Bitmap Proxy (can be accesed through Asset Manager).

Loading bitmaps in VrayHDRi produces especially good result when it comes to bump maps, which they come out crisper and sharper (but at same time, disable filtering). Credit for this advice goes to Vlado and Bertrand Benoit.

 

http://forums.cgarchitect.com/72249-vray-optimiation-print.html

[Nicolai Bongard]

Also:

Since V-Ray version 2, VRayHDRI will load the texture the first time it is needed during the actual rendering, rather than at the start of a frame. Textures that are not needed (for example, because their materials are not needed for the particular camera angle) will not be loaded at all.

When using tiled OpenEXR or TIFF textures, it is recommended to turn on the Filter maps for GI option in the Global Switches section; otherwise V-Ray will be forced to almost always load the most detailed version of the texture.

 

https://docs.chaosgroup.com/display/VRAY3MAX/V-Ray+Bitmap+Texture+%7C+VRayHDRI

[Francisco Penaloza]

I don't trust this, I haven't tested with the latest release for V-Ray (up to today 3.05.04), but while working on a large project on V-Ray 3.0 I had lots of gamma issues with the textures, Chaos group recommended to switch to VRay HDR instead, the project got extremely slow to work with, it was a large development, large landscaping, and many building, everything XREF and proxies. Every time I had to fix a material 3D Max material editor took several seconds to load. the sad part was that Vlado created a script to change all regular bitmap to Vray HDR shader but you could not take it back.

So we had to bite the bullet and keep finishing part of the project like that while another artist was manually changing all textures back to regular bitmap and using regular bitmap loader.

Chaos group worked on that file for a while then they developed the VRay bitmap loader, that should fix the problem, but never tried on production.

 

Using larger bit depth images for Bump map and Normal map it helps you to get better looks but for diffuse, specs and other there is not much difference, this does not apply if you are working on game engines, where the compression works better on larger bit depth images.

 

My recommendation would be to test this technique on small medium and large project but before to go to production.

Most of this features and tested in very small scenes so when you put it in production is when you really see if they apply to you or not.

[evanmichalski]

My recommendation would be to test this technique on small medium and large project but before to go to production.

Most of this features and tested in very small scenes so when you put it in production is when you really see if they apply to you or not.

 

I'm gonna do some testing this weekend and I'll get back to you guys with my results. Thanks for the responses btw.