I think that the meaning in this context is the 8th and last in the OED list of meanings of 'rendition'.
The BIM definition of Clash Detection makes it clear that it is a matter of recognising merging elements in a represented form (diagrams for example) which would not actually be buildable in three dimensions on the ground.
Thus Clash Rendition is the overcoming of that problem and seeks to represent matters properly in concept so that the eventual building is not compromised.
There may well be an overlap with other meanings (in the sense of 'removing' one thing from another, that is to say the 'resolution' of clashing concepts) and this may have caused some confusion. Nevertheless it is my own view that the word is suitable, albeit in an overlap of meanings and it is my own understanding that 'representation' is the primary focus in the terminology.
The OED gives 'representation' as the equivalent in its heading :
- Visual representation or reproduction; an example of this..
1959 E. Pulgram Introd. Spectrogr. Speech xiii. 89 I chose a sustained sound... The sketch of Fig. 11 is a complete and exact spectrographic rendition of it.
1978 Amateur Photographer 2 Aug. 109/2 A polarising filter may be used to darken skies without affecting the rendition of foreground detail.
1982 Byte Apr. 264/2 ‘What you see is what you get’ (or wysiwyg) refers to the situation in which the display screen portrays an accurate rendition of the printed page.
1989 J. Updike Just Looking 76 Modigliani..of modern artists adhered most closely to the classic and Renaissance ideal of design extracted from an attentive rendition of the real.
2001 Art Room Catal. Autumn 59/2 Printed with a faithful rendition of the doors into the Room de Luxe of Mackintosh's Willow Tea Rooms, 1903, this phenomenally elegant bed linen creates an opportunity to completely reinvent a bedroom with fin-de-siècle chic.