Is Transparency Rendering Slow in C4D?

[Per-Anders]

Cinema uses a hybrid render engine. It's worth remembering that C4D materials are somewhat more intelligent that LW ones and as such do not require you to make an air layer around anything transparent. If you simply set the IOR to 1.0 in the transparency channel you will be looking at a scanline transparency which will render faster, also turn off fresnel (unles you want additional reflections). You should also think about reducing your raydepth, in the render settings to optimize scenes involving transparency.

[LucentDreams]

3 areas lights yous ay, are there three area shadows too? area shadows with transparency can be very slow.

[RenderTITAN]

In my experience, transparencies add just to much to the render times. Of course if you are doing only a still or small animation, it can be bearable, but the bigger the project, the more you really should be looking for other techniques to optimize your render times. It is always a battle between time spent optimizing verses time rendering.

M

[vid2k2]

As you'll find out, the defaults are at times overkill.

As mentioned the render settings can be reduced from 15-5-15
to 6-5-6 or in the samples below 8-8-8

I used the same same stage but removed the backdrop and replaced that
with a background with the #1 gradient, adjusted

I used the same 3 lights
- area-area @80
- area-soft shadows @50
- area-soft shadows @25

Render times with Best jpg @ 72 dpi:
image 1= 0:30
image 2= 1:06

Try to stay away from the SLA shaders as they increase render time and
can be easily built

Hope this helps

[rickmorgan]

Thanks everyone for your help! I found out that rendering with the refractions option turned on in the render settings is the main culprit. If I turned that off the render times went WAY down. But still averaging roughly 3 minutes. And then if I have the reflections option turned on to reflect only the floor and sky that drops it down some more. Then I just add in a HDRI image to the sky to get nice reflections on my surface.

This is basically what I did in LightWave - turned off raytrace for reflection and refraction and put in an image invironment for realistic looking reflections.

Thanks again everyone. Now I will play with the area light and render depth settings you all suggested.

[rickmorgan]

Thanks vid2k2! That is very helpful. I will play with those settings to see what I get.

[LucentDreams]

instead of "reflecting" the HDR you can put in the environment channel then you have no need for reflections.

[rickmorgan]

That's an interesting idea LucentDreams. A few weeks ago I posted a question asking if people typically (for reflection images) put an image in the environment chanel of a material or in a sky or environment. The consensus was to put it in the sky so all your objects would reflect the same thing without having to put an image into each and every material. BUT, if it saves on render times it's worth putting it into every material.

I'm going to give it a try. I curious to see if it renders in less time and if the reflections are different than from a sky.

Thanks!

[rickmorgan]

Funny, the reflection in the sky vs. the reflection in the environment chanel made only a 1 second difference. And I made sure when I did the reflection in the material chanel render I selected "none" in the reflection option in the render settings. Maybe sky reflections and environment reflections are treated the same in the renderer???

[LucentDreams]

well if you only reflecting sky and floor then it is almost the same, the advantage of environment is that it has a special Exclusion option This makes it so all object while not reflecting still block out the sky. As well if you have one thing where reflections are crucial you can turn on reflection without worrying about those render settings.

[georgedrakakis]

this is a nice tutorial covering realistic glasses:
http://planetpixelemporium.com/tutorialpages/glass.html

[rickmorgan]

Thanks georgedrakakis, I did go through that tutorial. I'm getting close!

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