Page 1 of 1

problems with Cycles !

Posted: Thu Sep 20, 2012 10:40 pm
by dhuvelle
Hi, I just began to use Blender and I just think it's great !

I'm having troubles with the Blender's Cycles render mode. I'm on an iMac 2,5 GHz Intel Core i5, AMD Radeon HD 6750M 512 MB. I found on internet that Cycles was optimum when used with Nvidia's cards but on my mac I've been able to install "CUDA". I wonder if I can run Cycle with my GPU instead of my CPU.

so here is my problem, when I select GPU and start a render this appears, ...

message : "ERROR OpenCL build failed: errors on console"


does anyone can help me please ?


Posted: Thu Sep 20, 2012 11:16 pm
by Tehrasha
Ok, I am no expert on Cycles, CUDA or OpenCL... but from what I can glean from the wiki, CUDA is for nVidia chips, and AMD/ATI chipsets like yours require OpenCL. So I am not sure what you mean when you say you installed CUDA.

The error you see is Blender attempting to build the OpenCL kernel for your video card and failing. (open the Blender console, or try running Blender from a command line and see if it spits out more details about the error)

You do have OpenCL 1.1 or higher installed, yes?

The use of OpenCL in Blender is currently listed as 'experimental', so expect chaos. :)

Posted: Thu Sep 20, 2012 11:43 pm
by dhuvelle
I don't know how to install OpenCL. Do you know where I can find it ?

Posted: Fri Sep 21, 2012 6:52 am
by farbw3rk
[quote="dhuvelle"]I don't know how to install OpenCL. Do you know where I can find it ?[/quote]


OpenCL should come with an actual driver-package for your GFX-Card. Anyway, you are running OSX (i think? Or do we talk about a Bootcamp install on your iMac?) so which Version do you run? AFAIK OpenCL is included in OSX, OpenCL1.0 support should be within OSX10.6.x already - I don't know which spec Lion has (1.1/1.2?).

Posted: Fri Sep 21, 2012 2:33 pm
by dhuvelle

my OS is 10.7.5 (Lion)

here is a screenshot of the user's preferences panel. OpenCL is recognized by Blender on my Mac so I think OpenCL is installed. Today I tried to use the GPU mode and it show me that.


with the CPU selected,


why the GPU render mode show me this image ?


Posted: Fri Sep 21, 2012 6:22 pm
by farbw3rk
ok - seems like clay-rendering?

take a look here:
(Q: [url= ... _Rendering]2.6 RefManual[/url])
[quote] OpenCL

Implementation not finished yet, marked as experimental feature.

Rendering using OpenCL is not yet fully supported, but it is being worked on so we can support more graphics cards. Currently only simple clay rendering is supported, due to our full kernel not compiling with the AMD OpenCL compiler.

The first time rendering is done, the kernel must be compiled for your GPU architecture. Since Cycles is quite complex compared to a typical GPU kernel, compilation may take from 40 seconds to a few minutes, and may also up about 2GB of memory, depending on the graphics card model.

OpenCL version 1.1 or higher is required. [/quote]

Posted: Sat Sep 22, 2012 1:58 am
by dhuvelle
OK thank you !

So I just have to wait until blender Cycles will be fully working with my GPU. thx because I just started to play with blender and 3D stuffs so I don't understand everything :)

does anyone knows the release time for this update ?

thx a lot