Environment Map Issue?

[bdokertur666]

Hi everybody,

I have a little problem about this environment map thing. When I try to put some environment map as a bitmap at the background, my reflected or refracted objects are behaving like they are transparent through the background map. So how can I fix this problem? By the way I'm using a invisible plane for the ground to create shadows of the objects on it by using matte&shadows or vraymapwrapper.. If you have some better opinions about this, I will be greatly appreciated. Thanks..

[mienq.blom]

Where did you add the background? Under environment & effects (shortcut 8) or under render setup - GI environment or reflect/refract environment? Are you working with vray?
I have found adding the background into GI environment works best. Its not refraction youre seeing. Its the background reflecting on your objects.
If that doesnt work, I could only suggest you model a "studio" and assign a background material to these studio planes. This could be a normal material or a light material (to fake a GI).

[stef.thomas]

Is this a 360° environment map or just a straight photo? If it is just a single image set to screen mapping then you will not get realistic reflections/refractions.

One way round this problem is to have taken some photos facing in the opposite direction and create image planes to give the model an environment to reflect.

Ideally you would want to use a 360° spherical panorama for your reflections though.

[bdokertur666]

I used '8' shortcut background section environment map under the environment&effect. I'm working with vray ofcourse. One of my friend told me also making a plane or box at the back and apply that bitmap on it. But how can I arrange the view in perspective because it won't be seen as in these render pics above. Also what do you mean exactly with making the studio thing. My guess I will make a box thing and make them invisible so the reflections from the background map will be cut..
I tried to put it also in GI but still there are some transparency reflections. Although I put a single vray default material on the ground (didnt arrange any reflection or refraction), now the ground also behave like transparent at the render.. As I mentioned I did not use any reflections..

[stef.thomas]

If this background photo is all you have then it's not really going to work. At the moment you have no environment for your objects to reflect/refract. All there is is the background image which is projected straight through from the camera, so all your reflections/refractions are projected in the same manner which is why it appears to look transparent.

[bdokertur666]

Is this a 360° environment map or just a straight photo? If it is just a single image set to screen mapping then you will not get realistic reflections/refractions.

One way round this problem is to have taken some photos facing in the opposite direction and create image planes to give the model an environment to reflect.

Ideally you would want to use a 360° spherical panorama for your reflections though.

It isn't even necessary that objects has to reflect any environmental look, I can even use HDRI for that. I just want to see a background image and put my object on it with a proper perspective view. And I want metallic reflections on my objects thats all.. By the way yes, I use a straight photo that is set to screen mapping.
At the images that you see in it there is a shelter. I want that shelter to be reflected as a stainless steel and at the top of it I want a glass effect. That may be one of the transparent side and if it is necessary I can apply hdri map to make it look more realistic. But for now I have to fix this transparency look for the reflections..

[mienq.blom]

I know exactly what youre talking about - i had the same thing a while back.

Like i said, its not transparency. It is only reflection youre seeing. Even totally matte objects reflects the background!

1- try removing the background from shortcut8 and rather put it in your GI envirionment slot under render settings (shorcut F10). Make sure the refraction/reflection slot stays empty! Then see if theres a change.

2- if that doesnt work, I would still suggest the studio thing. Make sure you have NO environment bitmap in any of your settings. Just tick the GI environment on with the default light blue colour. Create a "room" around your scene. With 4 walls and a floor. Assign your background bitmap image to this box as a material! this way, you can use UVW mapping to allign the background the way you want it.

3- if all else fails.. PHOTOSHOP!

[mienq.blom]

Ok i went and tested the scene quick. So this is what works and what i would suggest:

You remove all the bitmaps from any environment settings (only switch on GI environment with the default blue colour)
You draw one big plane as a background screen to your scene. (this would be like a green screen effect).
With the plane selected - right click and untick receive shadows.
Create a material with the desired background bitmap as diffuse and map it 1:1 tiling. Make sure your plane is not real world mapping! Then assign your background material to this plane.
Now, make sure your plane faces the camera exactly (in other words, the camera angle falls perpendiculour to the planes face.)
Go to your camera view - then you can adjust the size and position of your plane while in camera view - so it matches your scene as you want it.

This is the best i could figure out.

[bdokertur666]

I know exactly what youre talking about - i had the same thing a while back.

Like i said, its not transparency. It is only reflection youre seeing. Even totally matte objects reflects the background!

1- try removing the background from shortcut8 and rather put it in your GI envirionment slot under render settings (shorcut F10). Make sure the refraction/reflection slot stays empty! Then see if theres a change.

2- if that doesnt work, I would still suggest the studio thing. Make sure you have NO environment bitmap in any of your settings. Just tick the GI environment on with the default light blue colour. Create a "room" around your scene. With 4 walls and a floor. Assign your background bitmap image to this box as a material! this way, you can use UVW mapping to allign the background the way you want it.

3- if all else fails.. PHOTOSHOP!

I tried your no. 1 suggestion and didnt work. If I deactive the background from shortcut 8 the background wont be appear in the render. And still there are silly reflections maybe not appeared like hundred percent transparent but I didnt even wait for the render time until it ends.

To your second suggestion, I made a box that big enough to include my objects and light in it. And final render is looks like in my attachment image. There is a reflection on the ground as you see like in red and grey colour that I didn't even expect that but it looks good anyways. Also generally it looks a little dark maybe it will be gone with the intensity of the vray light. By the way I can't get any global ilumination right as I'm not mistaken here because there is a closed box and I'm rendering in it.. Make it invisible to see the background image. Hope this invisiblity not effect GI..

To your last suggestion, I think it is the only way that this thing can be done.. If I want to put these objects to the photoshop, how do you prefer to render the scene with the ground colour or the other things for accurate selectivity in photoshop. For example I might include the reflections on the ground that can looks just like in my final render at the photoshop.. (I'm telling this if I can't do a photoshop reflections here, but I will try)

[mienq.blom]

haha! not a closed box! its like a box without a backside or a top. So its like a floor with 3 walls.
but try my 2nd suggestion with just one single "background plane" - i think that might work best!