my renders look weird

onixgraphics

hi there, i'm haaving trouble when it comes to rendering my scenes. whenever i render any scene it ends up looking like the image below. it always ends up looking pixelated. can anyone help

rames44

If you mean the graininess, this might be IRAY failing to converge before hitting your render limits. More light in the scene will frequently help, or you can increase the render limits (number of iterations, convergence)

Chezjuan

^ This. It is definitely Iray hitting one of the limits. 

Do you use the default settings under "Progressive", or do you modify them? If you use the defaults, I would guess that it is hitting the time limit of 2 hours and ending the render. You can check for sure by going to Help -> Troubleshoot ->View Log File after a render. The log file will tell you what stopped the work.

When doing a final product, I usually set my Iray renders to 10 hours (36,600 seconds). Most of my renders will complete in less time than that. I also set the number of iterations to maximum (15,000) because I've had one or two more complex scenes stop early when they hit the default of 5000 and I'd rather be safe than sorry.

Peter Wade

Iray renders can take a very long time depending on how complicated the scene is and how powerful your computer is. Iray continues to improve the image until it reaches one of it's limits. As Chezjuan says the default time limit is 2 hours. If you think the render looks good enough you can stop an Iray render and save the image before it finishes.

If you have got an Nvidia graphics card Iray can use it's GPU to render faster. Go to the advanced tab in Render Settings and see what devices are shown under Photoreal Devices and which are checked. You will always have the CPU available, if your graphics card is compatible it will be shown there. But Iray will only use the graphics card if the scene and all it's textures will fit into the video ram on the card. If the scene is too large it will go back to CPU only.

I have heard that Iray renders best with more light, and you can get low light effects by keeping the lights bright and using the tone mapping settings in render settings as a virtual exposure control bit I haven't tried this.

Alternatively you could use the 3Delight rendering engine by selecting it in render settings. 3Delight is usually faster but has a different look from Iray, generally less photo-real looking.

y3kman

I personally just set the max time to zero. The render will now just stop when it reaches the number of iterations set or the convergence ratio.