Custom HDRI instead of Atmosphere + animated hdri

Started by BlackScvale, January 26, 2015, 08:09:14 am

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BlackScvale

Hi! This is my first post here :) I have learned allot from this forum already. Thank you.

I need some assistance with workflow. Is it possible to use my own custom spherical HDRI as a environment map in Terragen. Instead of the built in Atmosphere. Can this effect the lighting of the clouds.

Is it possible to render a animated sequence of HDRI s (time laps) to be used as a environment map in let say 3dsmax.

Cheers!
B

Dune

Welcome!

I think it should be possible to project it onto the background node, spherical, with the centre location copied to the image map shader. Then probably as luminosity in the default shader, or you'll get shadows on the background. But I have no experience with it, so if nobody answers, you might have to try some things.

Oshyan

Yes, this is possible, though probably not ideal. You could use the Background object (a sphere), but you would need to make it much smaller so that the luminosity and GI sampling work best. So, slightly larger than the default planet would be ideal I think.

Rather than explain at length how to do this, I've just attached a TGD project file that shows it. I made a copy of the Background object and made it much smaller, then added an image map shader fed into a default shader to provide luminosity. You can use your own EXR image in place of the one I used (which I did not include). I would suggest using higher GI settings than are in my file, but for speed and ease of illustration I left it at default.

- Oshyan

BlackScvale

Hi Oshyan, fantastic thanks! I am taking a look at the file now. I am trying to find the best work flow for a project.

Basically, adding animated Terragen clouds in to existing HDRI images. Using the HDRI images to light the clouds in Terragen so they have the same "look" as the HDRI . Then render as a sequence with a spherical camera. Use the exr sequence in for lighting in 3dsmax.

Cheers!

Oshyan

Sounds interesting. I'm curious to hear if it will work, I don't think I've seen anyone else doing that sort of thing before.

- Oshyan

Matt

The export part will work very well, but I would recommend increasing the sun's visible diameter to 1 or more.

For the HDR import and rendering of clouds, this might work in a general way to light the clouds, but it won't have much directionality to it. What I mean by that is, the sun in your HDR won't create self shadowing in the clouds to the same kind of quality that Terragen's built-in sun can. Very high GI detail settings will help, but there will be limitations to what it can do. At the very least you will probably need to heavily blur the HDR before bringing it into Terragen. But I'm very interested in making this work well in a future iteration of our cloud technology.

Matt
Just because milk is white doesn't mean that clouds are made of milk.