Maxon Cinema 4D Forum
Noob render question
Noob render question
by John Wooltorton on Sep 14, 2018 at 10:35:03 pm

Hey everyone, I am following this tutorial to create a glass texture.
However, when I click the render button, the scene goes black and can't see anything. Why is it? Thanks!

Re: Noob render question
by Brian Jones on Sep 15, 2018 at 12:35:22 am

that tutorial is from a much earlier version of C4D (which version are you using?) but it should work - the rest of the scene (the floor/background object and lights etc) are in the null called Stuff so if you don't have lights you might not see anything, you should because the default light should be on by default but it can be turned off. You also might not see anything if you are using a newer version which has specular inside the reflectance (which is the newer version of the Reflection the presenter is using). If you followed the instructions and had color off transparency on but reflection off with no specular to turn on you'd have a transparent object with no highlights and nothing to see.
If you have a light in the scene and specular or reflectance on and you still can't see it can you post the scene file so we can take a look?

Re: Noob render question
by John Wooltorton on Sep 15, 2018 at 5:20:30 am

Thanks for the reply. Here is the scene file:

Re: Noob render question
by Brian Jones on Sep 15, 2018 at 1:51:24 pm

Your world has nothing in it other than the logo and the Glass plane so it's a black logo against a black background (you can see the reflected light in the Glass pane though). Try adding a Floor object and you will see your logo.

The logo material contains two images " (metal_gold_dark) and (metal_gold_dark)" which you didn't provide because of this the logo is rendering black since that's what you get when a texture file is missing. If you did get the .dds files with the logo .obj file then try Save Project With Assets to include the .dds files, if you only got the logo.obj file and the logo.mtl file but no .dds files you are going to have to make your own texture for it (or remove the references to the missing images in that one). Try just adding a plain C4D material on it.

since these are the missing textures listed when I import the .obj file it's obvious it's from AE with VideoCopilot installed and since I have neither I'm not seeing them. (metal_gold_dark, ./-o 0.000000 0.000000 -s 1.000000 1.000000 C:/Adobe/Adobe After Effects CC 2018/Support Files/Plug-ins/VideoCopilot/Materials/Pro_Shaders_2_maps/Metal_maps) (metal_gold_dark)...

Re: Noob render question
by John Wooltorton on Sep 15, 2018 at 2:33:02 pm

How could I forget the texture files!! Here is the new scene file:

Now I can see something, but nowhere near the glass texture. I believe I followed the steps correctly on how to create the texture with the adjustments I made due to different versions. My guess is that I have no idea on how to create a proper scene. I can see a reflection from the logo so I think it is done correctly, but the texture is just not glass.


Re: Noob render question
by Brian Jones on Sep 15, 2018 at 3:05:05 pm

that .rar won't open for me but it doesn't really matter I think. The main difference between the tutorial and your scene is that he is using a complete studio around the teapot (well, it looks like a GSG cyc floor and one of GSG's studio images as lighting) the point is there is something to reflect on the teapot and that is what sells the look for all reflective objects. If you put a reflective object in a blank black environment (which is what you get with one object in the scene in C4D) the result is always not what you want. I have to go out at the moment but I'll do an example when I get back.

Re: Noob render question
by John Wooltorton on Sep 16, 2018 at 9:27:24 pm

Hello, I am still looking forward to your help. Hope I can learn from you ☺

Re: Noob render question
by Brian Jones on Sep 16, 2018 at 11:43:43 pm

Busy weekend so far, I did a few example renders but might not be able to post anything until tomorrow .

Re: Noob render question
by Brian Jones on Sep 17, 2018 at 8:05:54 pm

So if you look at a glass in the real world you only see it due to the light it reflects, the way it changes the objects behind it (visually) and any surface imperfections (which are always there - no matter how small).
In 3D there's nothing to reflect by default so you have to provide the scenery, either by putting in lights, luminant objects, using a Sky object with a texture on it etc.
The transparent texture should also be considered, while the IOR of 1.6 in the glass material will distort things behind it, some absorption and roughness in the reflection help as well. Using the layer fresnel in the refection is a good idea too.
The shape of the object is important too. The round teapot shows off the lights well since the round shape will always reflect light back to the camera no matter where the lights and camera are. A flat surface like your logo is going to be a problem because the lights and camera need to be in just the right place for the light to get reflected to the right spot (where the camera is). It would help a lot to bevel the the edges of the logo to give an 'edge glint' but your object is really hard to bevel due to it's construction. It would be a lot easier to start with the splines that were used to make those two objects and Extrude them in C4D where you could add a bevel very easily but you would still have to pay attention to where the lights (or other objects) are to reflect back to the camera the way you want.

Here's a teapot and two flat glass planes with one light in a otherwise blank scene, you can't even see the planes since the light is not in the right position relative to the camera.

Here's the same scene with a stage object placed in

better but no reflections of the light, no shadows. Because it's the simple (fast) renderer shadows are not going to show unless there is some color/absorption in the material

Light reflecting off/through an object and onto the surroundings is Caustics which is enabled in the render settings and in the lights

This is all with the standard renderer. If you use GI you get much better glass and surroundings integration but it takes a lot longer to render, in a addition you can light the scene with an HRDI texture which also reflects in the glass.


This all only scratches the surface of all that's involved but it's a start. Reflective (non-transparent) surfaces are the same thing no metal/shiny thing looks good until it has something to reflect whether it real geometry, an image attached to a sky/big sphere or an image in the environment channel of the material at least.

Re: Noob render question
by John Wooltorton on Sep 17, 2018 at 10:02:01 pm

Wow, that's a lot of information, I really appreciate it. Is it possible for me to download the example file you have created so I can have a more thorough understanding of it? Like, I don't even know what a stage object is, and want to know how you placed the light etc. Having the example file as a starting point would help me a lot when following online tutorials.


Re: Noob render question
by Brian Jones on Sep 17, 2018 at 10:09:45 pm

I meant to add that, here you are.