robkar97 Posted September 11, 2007 Share Posted September 11, 2007 Hi, I am doing an interior with large windows. It's a daylight scene so it's pretty bright. I've used: - a daylight system (mr sun and mr sky) - a few area lights indoors. - Logarithmic exposure control The backdrop is a 360 panorama (retusched in Photoshop) that is mapped on a cylinder (without top and bottom). I want to use geometry for the background because the view from the individual windows is vital to the client. I've managed to setup the interior lighting ok, but the background is overexposed and washed out. I've already gone to object properties and deselected "generate gi" and "receive gi". The material is not self-illuminating, 0 specular level and black specular color. Additionally, the alpha channel shows everything is opaque even though I hide the background and the windows are transparent Sincerely, Robert Link to comment Share on other sites More sharing options...
chiquito Posted September 11, 2007 Share Posted September 11, 2007 try using a HDRI. That should work fine with lights and mooding of your scene. Link to comment Share on other sites More sharing options...
Fran Posted September 11, 2007 Share Posted September 11, 2007 You can also control the appearance via the Output rollout of the Bitmap Properties dialog. Link to comment Share on other sites More sharing options...
AJLynn Posted September 11, 2007 Share Posted September 11, 2007 Did you try the multipliers on the sun and sky? With the mr system, you don't use the exterior daylight flag in this situation, so the sun and sky are blown out proportionally to the rest of the render. Same thing happens with a real camera. But you can crank down the level from 1 to 0.03-0.06 depending on the setup. Link to comment Share on other sites More sharing options...
robkar97 Posted September 12, 2007 Author Share Posted September 12, 2007 Good ideas from all of you! I'll give it a try and post the result when I've come to a conclusion. About HDRI - will it suffice to render to a .hdr? I have never used that before but am very curious to find out how they work - it seems like the right way to go. Thanks everybody - this forum is really great. Sincerely, Robert Link to comment Share on other sites More sharing options...
chiquito Posted September 12, 2007 Share Posted September 12, 2007 HDRI, its really simple to use, you use a simple light rig. If interested, check for any tutorial on line, http://www.gnomonworkshop.com has a dvd, environments or something like that. some examples of lights rigs. If needed assitance for HDRI let me know, Regards Martin Link to comment Share on other sites More sharing options...
Stephen Thomas Posted September 12, 2007 Share Posted September 12, 2007 Why not make the cylinder a self-illuminated material and uncheck cast and receive shadows for this object. That way you can adjust the exposure of your background indepently of your lighting setup, via the strength of the self-illumination value. Link to comment Share on other sites More sharing options...
robkar97 Posted September 12, 2007 Author Share Posted September 12, 2007 That was exactly my first thought! I have unchecked cast and receice shadows but it will still light up like crazy since the sun will wash it out (even if the multiplier is set to 0.03). I can't find any Exclude-button on the mr sun... strange. This would have solved it I guess. Robert Link to comment Share on other sites More sharing options...
robkar97 Posted September 12, 2007 Author Share Posted September 12, 2007 Hi! I was curious - do you ues the hdri to light the scene or do you render .hdr images? Robert Link to comment Share on other sites More sharing options...
chiquito Posted September 12, 2007 Share Posted September 12, 2007 Robert: I see that you use mental ray? I use Vray, I guess the process would be the same, just some name changes here and there. make your scene, when happy, place a Vary light, go to modify and change the light type from plane to dome, that should be you ambient light, place a low number (0.2 multiplier, should vary depending on scene scale, etc and a color that matches your needs) On the material editor, check diffuse from a material, go down and choose Vray HDRI, then browse for a HDRI image (pick one from internet if in need, dosch design has some samples), once you did this: you will click and drag the material type (over material diffuse, bump etc on the material editor on the right, it should read HDRI or something like that, so you click and drag that to the material sample, click the type of wraping you need and rotate to get the correct ilumination. Then click and drag material (Hdri) to environment. Last, place a direct light with Vray shadows on from the same orientarion as the Hrdi, as a main focus of light. This should let you export any type of channel, alpha, background, etc. I attach some images of the process, in case it was a little bit confusing, let me know if you need anything else. Martin Link to comment Share on other sites More sharing options...
robkar97 Posted September 12, 2007 Author Share Posted September 12, 2007 Hi Martin! You're the man! Link to comment Share on other sites More sharing options...
chiquito Posted September 12, 2007 Share Posted September 12, 2007 did you mange to get the rig working? Link to comment Share on other sites More sharing options...
robkar97 Posted September 12, 2007 Author Share Posted September 12, 2007 I've bookmarked your post and will give it a try somewhat later... I have a deadline tomorrow at noon, and don't dare to go into unchartered terrain :-) But HDRI seems like a very nice feature. I'll pay a visit to Dosch too. Link to comment Share on other sites More sharing options...
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