Vray for Max - HDRI questions - Use in windows of flat images

[kevin.retrodesign]

Hello,

 

I'm a beguinner in rendering so please forgive me if I'm asking something absurd here.. However I must give it a try..

 

I have been testing Vray (version 1.5) in 3D studio (version 9-32 bit) and so far I have been pleased with some of my results. However, after having a glance at HDRI based renders I believe that they can add that little extra information that does just the trick to make it look real.

 

My questions:

 

1: Can I create an HDRI file from regular photos?

 

2: Can I create a flat HDRI, instead of spherical to be used in dome lighting? My question here is about using a single photo applied to a window in an interior scene to produce realistic reflections on the interior objects, without having to gather the complete scene around it outside since it's never going to be seen?

 

3: if the above is not possible, how can I control the scale of an HDRI applied to a dome? How do I know that the dome has the same scale as it should have in relation to the model and can the image be rotated to face specific views from the interior?

 

Sorry for this long thread but there's a lot going in my mind and my research has given me no results for these questions..

 

Looking forward your reply

 

Best regards

[braddewald]

1) You can create an HDRI file from regular photos but it is pretty tricky if you want good results.

 

2) I wouldn't apply the bitmap to the window even if it isn't going to be seen. I would put the bitmap on a vraylightmaterial and assign it to a box just outside of the window. Those should give you the reflections you want.

 

3) You just need to place a geometric dome over your scene and apply the map to it (also using a vraylightmaterial). This way you can scale the map to fit your needs.

[kevin.retrodesign]

Hello Bradley and thank you very much for your suggestions.

 

What I want is to render an interior scene where there is a view towards outside and I wanted to have the photo of the outside showing on my render and, at the same time cause some realistic reflections on my objects based on that same photo. I'll give your suggestion a try and apply the photo I have on a VrayLightMaterial.

 

I'm new to Vray and rendering so may I ask if there are any particular settings I must be aware of when applying the photo to the material?

 

Looking forward your reply

 

Best regards

[braddewald]

Just create a new vraylightmaterial and load up your image. There's not really any special settings you have to be aware of. Do a couple test renders to make sure everything is working properly, of course. You will probably have to increase the multiplier of the vraylightmaterial in the material settings to get it to show up properly in the rendering. Also, if you have a direct light (sun) coming into the scene through the window, the object you have your vraylightmaterial applied to may get in the way so just right click it, go to object properties, and uncheck "cast shadows."

[kevin.retrodesign]

Hello and thank you once more for your help.

 

A couple questions more, though.. I'm not using Vray Sun or other ambient light outside the scene. I'm just using a regular VrayLight that illuminates the entire opening. Should I replace this light with a VraySun in order to achieve more realistic effects?

 

Also, in case there is no significant change into lighting and I keep the VrayLight, should I also turn off the "cast Shadows" option or it doesn't get in the way of the VrayLightMaterial?

 

Thank you very much for all your help

 

Regards

[braddewald]

If the background object is not in front of your vraylight (which it shouldn't be), then you don't need to turn off cast shadows, although I really don't think it would matter. As far as the vray sun goes, it all depends on the kind of look you want to achieve; if you want sunlight in your scene, then add a sun, if you don't then don't. It's all about how you want your scene to look.

[kevin.retrodesign]

Thank you Bradley,

 

I'll follow your suggestions.

 

Regards