View Full Version : Reflection maps.

01 January 2012, 01:00 AM
It seems to me that Blender deals with reflections in an entirely different way than any 3D app I have used.

I want to reflect an image in a surface as though it is an environment map, but the only way I can seem to make this work is by adding an image to the world and let my object reflect that. However, I can't get it to reflect the image and not also render the image in the BG.

I also can't figure out how to get several materials to have several different reflection maps. I am using the term "reflection map" as it is used in 3DS Max, Lightwave, C4D, Maya or Houdini just in case there is any confusion.

I have to be doing something wrong. I just can't believe that something this simple can't be done.

I'd really appreciate any help.


01 January 2012, 07:03 AM
I hope I understand your question:

Select your object's material you wish to add your reflection map into, then go to Textures tab.

1. Add a texture with type "image or movie", then attach your reflection map image to it.
2. Then scroll a bit down and from "Mapping -> Coordinates:" select Reflection.
3. Select a matchin Projection setting to fit your reflection map image.
4. Check Influense settings and play around with them to get the needed results

I hope this helped even a bit ;)

01 January 2012, 06:36 AM
You understood my question just fine and I have already done exactly as you suggested, but the results I get are unlike any 3D app I have ever used.

If I have a sphere reflecting a cube, the reflection map only appears where the cube is reflected and the reflection map is mixed with that raytraced reflection of the sphere. The rest of the sphere is reflecting black (assuming the sky is black). If the sky is white, the reflection shows up!

A reflection map in any other piece of software is like a big invisible (to the camera but not reflections) sphere in your scene with the image you want reflected mapped on it. Any other objects that are raytraced into the reflections on your mirror object occlude the giant invisible reflection image sphere off in the distance.

This should be really simple and yet I cannot get this to work at all.

01 January 2012, 03:40 PM
Do you mean like this?:

1. Anyway if you do, in right menu (property window) select world tab (the earth icon),
then directly select texture tab. This will allow to you add textures to the world. Then just slap your reflection reflection in there with proper settings.

2. From the world tab select "blend sky" and I noticed that horizon color as white and zenith color as blue works with daylight sky, but you can fizzle with those.

3. Then from first tab (render settings), go to Layers section and deselect "Sky".
This will hide the background sky from your render but it will still be visible in reflections.

01 January 2012, 05:34 PM
Yes, like that...sort of. Can you also apply different reflections to different objects? Say I wanted two spheres in that scene and each to be reflecting a different image.

And what if I did want a sky BG image that was renderable but was different from what was reflected in the spheres?

01 January 2012, 05:56 PM
Then you should look in to Compositing. That'll allow you to do pretty much anything with your elements if you render your elements on different layers etc.

I can only point you to look into these tutorials about Compositing:

It's awesome site, you can find a lot of tutorials from there for various things. I hope that helps.

All I can say is that it will all makes sense when you tune your brains in to the logic of how Blender works :)

01 January 2012, 06:29 PM
"Logic of how Blender works..." That's funny. Blender has reinvented how reflection maps are done in every other 3D application.

That is the antithesis of logic. Essentially, you are suggesting the only solution is a workaround? I'm sorry to hear that. I am, however, very thankful for your reply! Thank you, thank you.

01 January 2012, 07:51 PM
It's not a warkoround, the basics are the same. There are several methods how you can end up with the same results. Just study and you'll find out :)

01 January 2012, 07:52 PM

This functionality for reflection maps seems almost useless. I can't even think of a circumstance in which I would use this.

I am astonished that you can't just make a reflection map like any other piece of 3D software. Do you know of a place in the blender community where I could make this complaint where it would get more attention than here between you and me?

It isn't like I haven't been doing 3D since 1992 working on shows like BABYLON 5, STAR TREK, SPACE: ABOVE & BEYOND, or VFX heavy movies like THE DAY THE EARTH STOOD STILL, MASTER AND COMMANDER, BLACK HAWK DOW, MINORITY REPORT and on and on.

I'm really trying to get Blender used more in TV and film and then I run into nonsense like this and it is frustrating. I'm happy that they redid the UI in 2.5 making it actually understandable to a new user, but they need to bring features like this into alignment with the VFX industry if they really want to be taken seriously.

I'd love any guidance you feel like giving me with this.

Blender: it's a whole new world for me, every part of it.

01 January 2012, 07:57 PM
Lets make one thing clear: I'm nowhere near in a position to give you the facts of capability of Blender. However the basic feature as reflection is, that you are complaining about, sounds more like you just need to get a hang of things how tools and methods work with Blender.

I could point you towards which is a prime forum to ask help with Blender usage. And if you form your question in reasonable way I'm sure you'll find help very soon there.

01 January 2012, 07:59 PM
By the way, I just finished a TV pilot where every 3D shot was done by me and my team in Blender. I have some suggestions for how to get this software up to speed for real VFX work. Some of the feature implementations just seem to be out of this one.

I get that there are differences between Blender and the way other software works. Blender improves upon a lot of other aspects of feature implementations. E.g., the node based compositing tools are in many ways implemented BETTER than the $8000 NukeX.

It is not okay, however, to just accept bad implementations of other tools. The developers may just not have known better. If I have to erect an elaborate "rig" of controls to just do what should be three mouse clicks in any other 3D app, just to do reflection maps, that is a problem and it should be changed.

In the mean time, I will learn the work-around, and that is exactly what it is. In any other 3D app, you assign a reflection map, per material, and it just works. Click the reflection map button. Select an image. Render. Done

01 January 2012, 08:07 PM
But I sincerely tank you again for your help and guidance. Are you on facebook or twitter? I'll friend/follow you.

01 January 2012, 08:25 PM
Sure I use Facebook, but not that active on those things. I am almost certain though that if you ask that very same question in you will get an answer that will answer your question way better than I could ever answer :D

I don't know you and therefore I'm not questioning your reliability or the level of your profession. However we all should realise that softwares do certain things in different ways.
It doesn't mean it would be faking or illogical or not functioning, just different.

I'm tipsy by now so I'm not so sure what you are aiming at so I'm just telling you to perform your question to where I originally told you to visit so you would get a proper answer :)

01 January 2012, 08:31 PM
>However we all should realise that softwares do certain things in different ways.
It doesn't mean it would be faking or illogical or not functioning, just different.

Yeah, I'm just assigning a value judgement. "Different" can mean "better" or "worse." In this case, the implementation is worse than any other mainstream product.

>I'm tipsy by now

I'm envious.

>I'm just telling you to perform your question to where I originally told you to visit so you would get a proper answer :)


01 January 2013, 07:32 PM
Of course, it was really my lack of understanding of Blender itself. To do what I needed involved using render layers.

01 January 2013, 07:47 AM

It's closer to the average technique in other softwares and it lets you apply different ref maps to different materials.


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