Openexr and Vray HDRI

V-Ray V-Ray for 3ds Max General
1

Using the dome vray light - is there any advantage in using the VrayHDRI as the texture map for the light over using a EXR through the bitmap (making sure its a true 32 bit bitmap)?

Using the standard Max bitmap has advantages as all the HDRI panos that I have made I store in openEXR so I don’t need to convert them (they are very large).

the workflow is slightly different with convolving the bitmap but the result is the same as far as I can tell.

the Multiplier function: what does the multiplication factor actually mean: is 2.0 a stop above 1.0 ?

2

actually you don’t need to convert an exr to radiance before loading it in a vrayhdr map. exrs will work just fine as they are.

3

wow thanks for that.
It is very interesting information indeed.

Wish I’d been smart enough to know that before - would have saved me a lot of time with the conversion thingy.

4

actually I just tried it - and it didn’t work.
It will only load HDR’s AFAIK

5

You can’t load exrs in the VrayHDR map. I discussed this with PGuthrie a while back and his view was that using exrs in a bitmap worked just as well, if not better. The few tests I’ve made seem to confirm this.

6

you’re right, sorry I posted that without double checking it. don’t know why I was sure they did work, but as you say they don’t.

7

yes using the RGBA32bitmap is just as good

But what does the mulitplication factor mean?

8

The only thing I miss is the vertical rotation from the VrayHDR loader. That is handy, and the vertical offset in the bitmap loader does seem to do the same thing.

b