long rendering time with irmap mode (animation rendering)

[stormchaser]

ok folks, i am going crazy here, i have an animation where building grows, you know the usual effects, boolean, scale, etc etc.. now i cant bake the lighting solution for it so i chose irradiance map + brute force with irradiance map set to animation prepass and calculated the map for all the frames. took me some 24 hours for 1min29sec of animation.

now i put it on the final rendering with irmap mode set to animation rendering, but it is taking ages to render each frame.. over 17mins per frame, while it is taking 1min45 secs to render the same frame with irmap mode set to single frame. so at one hand vray calculates gi and render the image and takes only a min and 45 secs and on other hand with already calculate gi it takes 17mins.. something is seriously wrong... help me out mates...

[AubreyM]

Maybe this could have something to do with it. From the vray help file.

 

Interpolation samples - this is the number of GI samples that will be used to interpolate the indirect illumination at a given point. Larger values tend to blur the detail in GI although the result will be smoother. Smaller values produce results with more detail, but may produce blotchiness if low Hemispheric subdivs are used. Note that if you use interpolated irradiance maps (i.e. the Mode is set to Animation (rendering)), V-Ray will actually multiply this value by the number of irradiance maps used. For example, if you have the Interpolation samples set to 20, and the Interpolation frames to 2, V-Ray will actually use 100 samples to interpolate. This is done in order to preserve the blurring of the GI solution compared to a single frame irradiance map, however it also slows down the rendering. To speed up the rendering in that case, you can decrease this value to 10 or 5.

 

Interpolation frames - this determines the number of frames that will be used to interpolate GI when the Mode is set to Animation (rendering). In this mode, V-Ray interpolates the irradiance from the maps of several adjacent frames to help smooth out any flickering. Note that the actual number of frames used is 2*(interp. frames)+1 - e.g. the default value of 2 means that in total 5 irradiance maps will be interpolated. Higher values slow down the rendering and may produce "lagging" effect. Lower values render faster but may increase flickering. Note that increasing this value also increases the number of samples used for interpolation from the irradiance map - see the note for the Interpolation samples parameter.

[stormchaser]

thanks for pointing me out in the right direction, i will try these findings and report back.

[AubreyM]

Good Luck

[stormchaser]

the rendering time has come down significantly but still single frame is a lot faster about 4 times faster.. i think that is because irmap is too complex.

but thanks for the help, now i know what to keep in mind in my next project.

regards

[AubreyM]

You're welcome, glad it worked out.

[sanmb]

Also try to set IR map mode multiframe incremental and see if you can reduce rendering time.